I. Definition.
According
to the Pali-Vietnamese Dictionary, Sati or Mindfulness is Sammasati 
(p)—Samyaksmrti (skt). In fact, Right remembrance (Sati), the seventh of
the eightfold noble path, means remembering correctly and thinking 
correctly. The looking or contemplating on the body and the spirit in 
such a way as to remain ardent, self-possessed and mindful. Right 
remembrance means looking on the body and spirit in such a way as to 
remain ardent, self-possessed and mindful, having overcome both 
hankering and dejection. With the eightfold noble path, right 
mindfulness means the one-pointedness of the mind.      
Samyag-smrti
(skt), Samma-sati (p) or Right mindfulness means to give heed to good 
deed for our own benefit and that of other. *Right mindfulness also 
means remembrance including old mistakes to repent of and deep gratitude
towards parents, country, humankind, and Buddhist Triple Gems. *Right 
mindfulness also means the reflection on the present and future events 
or situations. We must meditate upon human sufferings that are caused by
ignorance and decide to work for alleviating them, irrespective of 
possible difficulties and boredom. *Correct (Right or Perfect)  
Remembrance or Mindfulness—Correct Memory which retains the true  and 
excludes the false—Dwell in contemplation of  corporeality. Be mindful 
and putting  away worldly greed and grief.  Correct mindfulness also 
means ongoing mindfulness of body, feelings, thinking, and objects of 
thought
Venerable Henepola Gunaratana perceived that Sati is an 
activity. What exactly is that? Well, this is one of those questions 
without a precise answer, at least not in words. Words are devised by 
the symbolic levels of the mind and they describe those realities with 
which symbolic thinking deals. Mindfulness (Sati) is pre-symbolic. It is
not shackled to logic. Nevertheless, Mindfulness can be experienced - 
rather easily - and it can be described, as long as you keep in mind 
that the words are only fingers pointing at the moon. They are not the 
thing itself. The actual experience lies beyond the words and above the 
symbols. Mindfulness could be described in completely different terms 
than will be used here and each description could still be correct.
To
Pho Nguyet, Sati or right Mindfulness is the pure consciousness or true
perception because we knew, about psychological view, the structure of 
sensations and perception as follows:
Sensations and Perceptions.
The
characteristics of sensation are common to all. First, the individual 
sensory organs are stimulated by a specific and different form of 
external or internal energy: vision  (eyes + material shapes = visual 
consciousness) is stimulated by electromagnetic energy (or light); 
hearing (ear + sounds = auditory consciousness), by sound waves; smell 
(nose + smells = olfactory consciousness) by new stimuli olfactory 
system; taste (tongue + tastes = gustatory consciousness by papillae; 
touch (body + tangibles = tactile consciousness) by a stimulus of the 
skin or body; and feeling (mind mental + objects = mental consciousness)
whereby the brain interprets the sensations it receives, giving them 
order and meaning. All perceptions are conscious ones and people are 
aware of things they are perceived and how they interpret them. 
Perceptions are limited from senses. "Sensation is essentially the 
process whereby stimulation of receptor cells in various parts of the 
body (the eyes, ears, nose, mouth, and surface of skin) sends nerve 
impulses to the brain, where these impulses register as a touch, a 
sound, a taste, a plash of color, and so forth. Perception, in contrast,
is the process whereby the brain interprets the sensations it receives,
giving them order and meaning" (Psychology, Wortman and Loftus, 1981). 
All perceptions are conscious ones and people are aware of things they 
are perceived and how they interpret them. Perceptions are limited from 
senses. So, the right Mindfulness is the real consciousness or pure 
perception. It is the clearance of consciousness. 
Sati is a 
subtle process that you are using at this very moment with perfect 
sense.  When we first become conscious of something there is a fleeting 
instant of pure perception just before we conceptualize it, or before 
identify it. That is a stage of Mindfulness (Sati). Ordinarily, this 
stage is very short. It is that flashing split in present-ksana just 
before we focus our eyes on the thing, just before we focus our mind on 
the thing, just before we objectify it as clamp down on it mentally and 
segregate it from the rest of existence as Venerable Henepola perceived.
It takes place just before you start thinking about it - before that 
little 'yak, yak' machine inside your skull says, "Oh, it's a dog." That
flowing, soft-focused moment of pure awareness is Mindfulness (Sati). 
In that brief flashing mind- moment you experience a thing as a 
un-thing. You experience a softly flowing moment of pure experience that
is interlocked with the rest of reality, not separate from it. 
Mindfulness is very much like what you see with your peripheral vision 
as opposed to the hard focus of normal or central vision. Yet this 
moment of soft, unfocused, awareness contains a very deep sort of 
knowing that is lost as soon as you focus your mind and objectify the 
object into a thing. In the process of ordinary perception, the 
Mindfulness (Sati) step is so fleeting as to be unobservable. We have 
developed the habit of squandering our attention on all the remaining 
steps, focusing on the perception, cognizing the perception, labeling 
it, and most of all, getting involved in a long string of symbolic 
thought about it. That original moment of Mindfulness just gets lost in 
the shuffle. It is the purpose of the above mentioned Vipassana (or 
insight) meditation to train us to prolong that moment of awareness. 
When this Mindfulness (Sati) is prolonged by using proper techniques, 
you find that this experience is profound and it changes your whole view
of the universe. This state of perception has to be learned, however, 
and it takes regular practice. Once you learn the technique, you will 
find that Mindfulness has a number of interesting characteristics.
 
II. Characteristic
Clearly
the Mindfulness is a shadow (image, light, sound, stimuli, etc…) that 
our senses are perceived fully from its form of emptiness. With the 
perfect sense, it is without space-time. The structure of space-time of 
the Mindfulness occurs in a present-ksana:
Space that contains a 
thing and the thing  that occupies its volume in the space are 
packed-tight or coinciding with themselves; they are one. When we see an
object, our eyes receive light from the surrounding object and 
translate it into nerve impulses that travel to the brain. Light 
arriving at the retina must pass through various other cells before 
striking the rods and cones, which cover it into nervous impulses. The 
impulses then pass through these other cells to be coded and organized 
before traveling over the optic nerve to the brain. I see the the 
object; in the true way, I see its light or image. The image is an 
emptiness on the retina and the character of the mind is the emptiness; 
they too are the emptiness, so we can see that object. The Mindfulness 
is an object, therefore It is empty and spaceless.
Time. When we 
see the object, after a shortest period of time (ksana) that object 
becomes immediately ureal or It is not yet Itself; It has a ksana old 
(Time).
When we see a first point of an object and we perceive 
it, we have a pure perception because three lifetimes are not capable to
be  gotten to the time being of the objcect because time always lasts 
in the infinite line of beginning and exinction and so on without 
ending. We can get the real (or first) point of the time being with a 
ksana [a shortest period of time] to the object.  When we perceive 
perfectly that object with no time thinking, we have the pure perception
or pure consciousness. In sum the Mindfulness is perceived fully here 
and now without space-time.
The characteristics of the 
Mindfulness are empty without time; for anything the Mindfulness is only
the clearance of Consciousness. Venerable Henepola Gunaratana also 
described this characteristics carefully and clearly as the following 
reference:
Mindfulness (Sati) is mirror-thought. It reflects only
what is presently happening and in exactly the way it is happening. 
There are no biases.
Mindfulness (Sati) is non-judgmental 
observation. It is that ability of the mind to observe without 
criticism. With this ability, one sees things without condemnation or 
judgment. One is surprised by nothing. One simply takes a balanced 
interest in things exactly as they are in their natural states. One does
not decide and does not judge. One just observes.
It is 
psychologically impossible for us to objectively observe what is going 
on within us if we do not at the same time accept the occurrence of our 
various states of mind. This is especially true with unpleasant states 
of mind. In order to observe our own fear, we must accept the fact that 
we are afraid. We can't examine our own depression without accepting i 
fully. The same is true for irritation and agitation, frustration and 
all those other uncomfortable emotional states. You can't examine 
something fully if you are busy rejecting the existence of it. Whatever 
experience we may be having, Mindfulness just accepts it. It is simply 
another of life's occurrences, just another thing to be aware of. No 
pride, no shame, nothing personal at stake - what is there, is there.
Mindfulness
(Sati) is an impartial watchfulness. It does not take sides. It does 
not get hung up in what is perceived. It just perceives. Mindfulness 
does not get infatuated with the good stuff. It does not try to sidestep
the bad stuff. There is no clinging to the pleasant, no fleeing from 
the unpleasant. Mindfulness sees all experiences as equal, all thoughts 
as equal, all feelings as equal.
Nothing is suppressed. Nothing 
is repressed. Mindfulness does not play favorites. Mindfulness (Sati) is
nonconceptual awareness. Another English term for Sati is 'bare 
attention.' It is not thinking. It does not get involved with thought or
concepts. It does not get hung up on ideas or opinions or memories. It 
just looks. Mindfulness registers experiences, but it does not compare 
them. It just observes everything as if they were occurring for the 
first time. It is not analysis which is based on reflection and memory. 
It is, rather, the direct and immediate experience of whatever is 
happening, without the medium of thought. It comes BEFORE thought in the
perceptual process.
Mindfulness (Sati) is present-time 
awareness. It takes place in the here and now. It is the observance of 
what is happening right now, in the present moment. It stays forever in 
the present, surging perpetually on the crest of the ongoing wave of 
passing time. If you are remembering your second-grade teacher, that is 
memory. When you then become aware that you are remembering your 
second-grade teacher, that is Mindfulness. If you then conceptualize the
process and say to yourself, "Oh, I am remembering" , that is thinking.
Mindfulness (Sati) is non-egoistic alertness. It takes place without 
reference to self. With Mindfulness one sees all phenomena without 
references to concepts like "me", "my" or "mine". For example, suppose 
there is a pain in your left leg. Ordinary consciousness would say, "I 
have a pain." Using Mindfulness, one would simply note the sensation as a
sensation. One would not tack on that extra concept "I". Mindfulness 
stops one from adding anything to perception, or subtracting anything 
from it. One does not enhance anything. One does not emphasize anything.
One just observes what is there - without distortion.
Mindfulness
(Sati) is goal-less awareness. In Mindfulness, one does not strain for 
results. One does not try to accomplish anything. When one is mindful, 
one experiences reality in the present moment in whatever form it takes.
There is nothing to be achieved. There is only observation.
Mindfulness
(Sati) is awareness of change. It is observing the passing flow of 
experience. It is watching things as they are changing. It is seeing the
birth, growth, and maturity of all phenomena. It is watching phenomena 
decay and die. Mindfulness is watching things moment by moment, 
continuously. It is observing all phenomena - physical, mental or 
emotional - whatever is presently taking place in the mind. One just 
sits back and watches the show.
Mindfulness is the observance of 
the basic nature of each passing phenomena. It is watching the thing 
arising and passing away. It is seeing how the thing makes us feel and 
how we react to it. It is observing how it affects others. In 
Mindfulness, one is an unbiased observer whose sole job is to keep track
of the constantly passing show of the universe within. Please note that
last point. In Mindfulness, one watches the universe within. The 
meditator who is developing Mindfulness (Sati) is not concerned with the
external universe. It is there, but in meditation, one's field of study
is one's own experience, one's thoughts, one's feelings, and one's 
perceptions. In meditation, one is one's own laboratory. The universe 
within has an enormous fund of information containing the reflection of 
the external world and much more. An examination of this material leads 
to total freedom. 
Mindfulness (Sati) is participatory 
observation. The meditator is both participant and observer at one and 
the same time. If one watches one's emotions or physical sensations, one
is feeling them at that very same moment. Mindfulness is not an 
intellectual awareness. It is just awareness. The Mirror- thought 
metaphor breaks down here. Mindfulness is objective, but it is not cold 
or unfeeling. It is the wakeful experience of life, an alert 
participation in the ongoing process of living.
Mindfulness 
is an extremely difficult concept to define in words - not because it is
complex, but because it is too simple and open. The same problem crops 
up in every area of human experience. The most basic concept is always 
the most difficult to pin down. Look at a dictionary and you will see a 
clear example. Long words generally have concise definitions, but for 
short basic words like "the", "is" or "but", definitions can be a page 
long. And in physics, the most difficult functions to describe are the 
most basic - those that deal with the most fundamental realities of 
quantum mechanics. Mindfulness is a pre- symbolic function. You can play
with word symbols all day long and you will never pin it down 
completely. We can never fully express what it is. However, we can say 
what it does.
 
There are three fundamental activities of 
Mindfulness (Sati). We can use these activities as functional 
definitions of the term: (1) Mindfulness reminds us what we are supposed
to be doing; (2) it sees things as they really are; and (3) it sees the
deep nature of all phenomena. Let's examine these definitions in 
greater detail.
Mindfulness (Sati) reminds you what you are 
supposed to be doing. In meditation, you put your attention on one item.
When your mind wanders from this focus, it is Mindfulness that reminds 
you that your mind is wandering and what you are supposed to be doing. 
It is Mindfulness that brings your mind back to the object of 
meditation. All of this occurs instantaneously and without internal 
dialogue. Meditation is not thinking. Repeated practice in meditation 
establishes this function as a mental habit which then carries over into
the rest of your life. You should be paying bare attention to 
occurrences all the time, day in, day out, whether formally sitting in 
meditation or not. This is a very lofty ideal towards which those who 
meditate may be working for a period of years or even decades.
Our
habit of getting stuck in thought is years old, and that habit will 
hang on in the most tenacious manner. The only way out is to be equally 
persistent in the cultivation of constant Mindfulness (Sati). When 
Mindfulness is present, you will notice when you become stuck in your 
thought patterns. It is that very noticing which allows you to back out 
of the thought process and free yourself from it. Mindfulness then 
returns your attention to its proper focus. If you are meditating at 
that moment, then your focus will be the formal object of meditation. If
you are not in formal meditation, it will be just a pure application of
bare attention itself, just a pure noticing of whatever comes up 
without getting involved - "Ah, this comes up... and now this, and now 
this... and now this."
Mindfulness (Sati) is at one and the same 
time both bare attention itself and the function of reminding us to pay 
bare attention if we have ceased to do so. Bare attention is noticing. 
It re-establishes itself simply by noticing that it has not been 
present. As soon as you are noticing that you have not been noticing, 
then by definition you are noticing and then again you are back to 
paying bare attention. Well, that all sounds very involved, but there is
nothing complex about it. It is just the words. It is just a thing you 
will learn to do by feel, the way you play baseball. Mindfulness creates
its own distinct feeling in consciousness. It has a flavor - a light, 
clear, energetic flavor.
Conscious thought is heavy by 
comparison, ponderous and picky. But here again, these are just words. 
Your own practice will show you the difference. Then you will probably 
come up with your own words and the words used here will become 
superfluous. Remember, practice is the thing.
Mindfulness (Sati) 
sees things as they really are. It adds nothing to perception and it 
subtracts nothing. It distorts nothing. It is bare attention and just 
looks at whatever comes up. Conscious thought loves to paste things over
our experience, to load us down with concepts and ideas, to immerse us 
in a churning vortex of plans and worries, fears and fantasies. When 
mindful, you don't play that game. You just notice exactly what arises 
in the mind, then you notice the next thing. "Ah, this... and this... 
and now this." It is really very simple.
Mindfulness (Sati) sees 
the true nature of all phenomena. Mindfulness and only Mindfulness can 
perceive the three prime characteristics that Buddhism teaches are the 
deepest truth of existence. In Pali these three are called Annica 
(impermanence) , Dukkha (unsatisfactoriness ), and Anatta (selflessness -
the absence of a permanent, unchanging, entity that we call soul or 
self). These truths, by the way, are not presented in Buddhist teaching 
as dogmas subject to blind faith. The Buddhists feel that these truths 
are universal and self-evident to anyone who cares to investigate in a 
proper way. Mindfulness is that method of investigation. Mindfulness 
alone has the power to reveal the deepest level of reality available to 
human observation. At this level of inspection, one sees the following: 
(a) All conditioned things are inherently transitory; (b) every worldly 
thing is, in the end, unsatisfying; and (c) there are really no entities
that are unchanging or permanent, only processes.
Mindfulness 
works like an electron microscope. That is, it operates on so fine a 
level that one can actually see directly those realities which are at 
best theoretical constructs to the conscious thought process. 
Mindfulness actually sees the impermanent character of every perception.
It sees the transitory and passing nature of everything that is 
perceived. It also sees the inherently unsatisfactory nature of all 
conditioned things. It sees that there is no sense grabbing onto any of 
these passing shows. Peace and happiness just cannot be found that way. 
And finally, Mindfulness sees the inherent selflessness of all 
phenomena. It sees the way we have arbitrarily selected a certain bundle
of perceptions, chopped them off from the rest of the surging flow of 
experience and then conceptualized them as separate, enduring, entities.
Mindfulness actually sees these things. It does not think about them, 
it sees them directly. When it is fully developed, Mindfulness sees 
these three attributes of existence directly, instantaneously, and 
without the intervening medium of conscious thought. In fact, even the 
attributes which we just covered are inherently arbitrary. They don't 
really exist as separate items. They are purely the result of our 
struggle to take this fundamentally simple process called Mindfulness 
and express it in the cumbersome and inherently unsuitable thought 
symbols of the conscious level. Mindfulness is a PROCESS, but it does 
not take place in steps. It is a wholistic process that occurs as a 
unit: you notice your own lack of Mindfulness; and that noticing itself 
is a result of Mindfulness; and Mindfulness is bare attention; and bare 
attention is noticing things exactly as they are without distortion; and
the way they are is Anicca, Dukkha, and Anatta (impermananent, 
unsatisfactory, and self-less). It all takes place in a flash-bang. This
does not mean, however, that you will instantly attain liberation 
(freedom from all human weaknesses) as a result of your first moment of 
Mindfulness. Learning to integrate this material into your conscious 
life is another whole process. And learning to prolong this state of 
Mindfulness is still another. They are joyous processes, however, and 
they are well worth the effort.
Mindfulness (Sati) and Insight 
(Vipassana) Meditation Mindfulness is the center of Vipassana meditation
and the key to the whole process. It is both the goal of this 
meditation and the means to that end. You reach Mindfulness by being 
ever more mindful. One other Pali word that is translated into English 
as Mindfulness is Appamada, which means non- negligence or an absence of
madness. One who attends constantly to what is really going on in one;s
mind achieves the state of ultimate sanity.
The Pali term 'Sati'
also bears the connotation of remembering. It is not memory in the 
sense of ideas and pictures from the past, but rather clear, direct, 
wordless knowing of what is and what is not, of what is correct and what
is incorrect, of what we are doing and how we should go about it. 
Mindfulness (Sati) reminds the meditator to apply his attention to the 
proper object at the proper time and to exert precisely the amount of 
energy needed to do that job. When this energy is properly applied, the 
meditator stays constantly in a state of calmness and alertness. As long
as this condition is maintained, those mind-states called 'hindrances' 
or 'psychic irritants' cannot arise - there is no greed, no hatred, no 
lust or laziness. But we are all human and we all goof. Most of us are 
very human and we goof repeatedly. Despite honest effort, the meditator 
lets his Mindfulness slip now and then and he finds himself stuck in 
some nasty, but normal, human failure. It is Mindfulness that notices 
that change. And it is Mindfulness that reminds him to apply the energy 
required to pull himself out of the soup. These slips happen over and 
over, but their frequency decreases with practice. Once Mindfulness has 
pushed these mental defilements aside, more wholesome states of mind can
take their place. Hatred makes way for loving kindness, lust is 
replaced by detachment. It is Mindfulness which notices this change, 
too, and which reminds the Vipassana meditator to maintain that extra 
little mental sharpness needed to keep these more desirable states of 
mind. Mindfulness makes possible the growth of wisdom and compassion.
Without
Mindfulness they cannot develop to full maturity. Deeply buried in the 
mind, there lies a mental mechanism which accepts what the mind 
perceives as beautiful and pleasant experiences and rejects those 
experiences which are perceived as ugly and painful. This mechanism 
gives rise to those states of mind which we are training ourselves to 
avoid - things like greed, lust, hatred, version, and jealousy. We 
choose to avoid these hindrances, not because they are evil in the 
normal sense of the word, but because they are compulsive; because they 
take the mind over and capture the attention completely; because they 
keep going round and round in tight little circles of thought; and 
because they seal us off from living reality.
These hamperings 
cannot arise when Mindfulness is present. Mindfulness is attention to 
present time reality, and therefore, directly antithetical to the dazed 
state of mind which characterizes the impediments. As meditators, it is 
only when we let our Mindfulness slip that the deep mechanisms of our 
minds take over - grasping, clinging and rejecting. Then resistance 
emerges and obscures our awareness. We do not notice that the change is 
taking place - we are too busy with a thought of revenge, or greed, 
whatever it may be. While an untrained person will continue inn this 
state indefinitely, a trained meditator will soon realize what is 
happening. It is Mindfulness that notices the change. It is Mindfulness 
that remembers the training received ad that focuses our attention so 
that the confusion fades away. And it is Mindfulness that then attempts 
to maintain itself indefinitely so that the resistance cannot arise 
again. Thus, Mindfulness is the specific antidote for hindrances. It is 
both the cure and the preventive measure.
III. Practice
From
the excerpt in the four Foundations of the Mindfulness, Venerable 
Sayadaw U Siilaananda have studied what are the Buddha ‘s teachings  to 
practice. Here in the summary the Buddha taught us how to practice the 
four foundations of mindfulness. So what are the four? "Herein, a monk 
dwells contemplating the body in the body, ardent, clearly comprehending
and mindful, overcoming or removing covetousness and grief in the 
world." It is a very short sentence but it has many meanings.
"Contemplating
the body in the body": That means when a monk practices mindfulness of 
the body he is precise. He contemplates the body in the body and he does
not contemplate the feeling in the body or he does not contemplate the 
person in the body and so on. He contemplates the body in the body. In 
order to have a precise object the Buddha repeated the words "body, 
feeling, consciousness and dhamma" in these sentences. So that means he 
is precise in his mindfulness of the body, feelings, consciousness and 
the dhammas. When he practices body contemplation he is ardent, he is 
clearly comprehending and he is mindful. With regard to the word 
"ardent" I do not know what other meaning it carries in English. This 
word is the translation of the Paa.li word "aataapii".
Now here, 
most English translations missed the point. They translate it as "having
overcome" or "having abandoned", or "having removed" covetousness and 
grief in the world. What is the practice for? What is this mindfulness 
practice for? It is for overcoming covetousness and grief. Covetousness 
means attachment and grief means ill will or anger. So, Vipassanaa or 
Satipa.t.thaana meditation is "for overcoming" covetousness and grief.
If
a person has already overcome covetousness and grief he/she does not 
need to practice. For this very purpose we are practicing mindfulness, 
but if we have already achieved this purpose we do not need to practice 
mindfulness. So, here we should translate it as "overcoming (at the same
time) covetousness and grief in the world," and not "having overcome." 
That means the yogi overcomes covetousness and grief as he practices 
mindfulness. I want you to be aware of this. (Here an explanation with 
reference to Paa.li grammatical construction would be helpful; but since
it would be too involved I have no choice but to ignore it.)
how
to do Mindfulness Meditation, Sakyong Mipham Rinpoche discussed, 
“Mindfulness practice is simple and completely feasible. Just by sitting
and doing nothing, we are doing a tremendous amount.”
As you 
start the practice, you have a sense of your body and a sense of where 
you are, and then you begin to notice the breathing. The whole feeling 
of the breath is very important. The breath should not be forced, 
obviously; you are breathing naturally. The breath is going in and out, 
in and out. With each breath you become relaxed.
Thoughts. No 
matter what kind of thought comes up, you should say to yourself, “That 
may be a really important issue in my life, but right now is not the 
time to think about it. Now I’m practicing meditation.” It gets down to 
how honest we are, how true we can be to ourselves, during each session.
IV. Conclusion 
In
sum, the Mindfulness is the clearance of Consciousness that is empty 
and without space-time. The Buddha’s teachings and the discussion of the
Venerables are demonstrated exactly. Vipassana or Mindfulness bases 
every step on "reality-as it is." Vipassana allows a meditator to 
experience moments of "no nutriment to the mind. This starts the process
of "detoxifying" the mind of its impurities. The first sentence is, 
"This is the only way, monks, for the purification of beings ... namely,
the Four Foundations of Mindfulness." So, at the very beginning the 
Buddha said, "This is the only way". The Four Foundations of Mindfulness
or the Practice of Mindfulness, is the only way for the purification of
beings ... Here the Buddha said, "This is the only way". 
This 
pure and unstained investigative awareness not only holds the fetters at
bay, it lays bare their very mechanism and destroys them. Mindfulness 
neutralizes defilements in the mind. The result is a mind which remains 
unstained and invulnerable, completely unaffected by the ups and downs 
of life. 
Reference 
DPVEDP: Buddhist Dictionary Pali-Vietnamse. Thien Phuc. Retreived at Quang Duc website: http://www.quangduc.com. 
Excerpt
from Mindfulness in Plain English by Venerable Henepola Gunaratana. 
Retreived at: http://www.purifymind.com/Practice. Html.
how to do Mindfulness Meditation. Sakyong Mipham Rinpoche. Retreived at the Quang Duc website. 
The Four Foundations of Mindfulness (A Summary).Venerable Sayadaw U Siilaananda. Excerpt from the Quang Duc website.
 Pho Nguyet