This is a very good book on Buddhism by a very well known teacher with great realization. I enclose part of the text for you to see.

Khenchen Palden Sherab Rinpoche is the author of works on Tibetan grammar, poetry, philosophy, and history. Several of his books are used in courses at the Central Institute of Higher Tibetan Studies. He has taught in Tibet, India, Nepal, England, France, Belgium, Australia, Canada, Russia, Puerto Rico, and throughout the United States. Khenchen Rinpoche is considered one of the greatest living scholars and meditation masters of Tibetan Nyingma Buddhism.

Like all sentient beings in this world, we have problems and fears. If we try to find the cause of our unhappiness, we may think that there are various things

and people in the world that cause our suffering, but this is not so. The external factors that bring sorrow at one time can bring joy at another time. We have to look inward to find the source of our problems. Everything we experience, whether pleasant or unpleasant, is the result of causes and conditions related to our state of mind. The mind produces all our experiences and perceptions. When we tame the

mind so that it rests calmly and clearly, then all our experiences are open and relaxed. When the mind is peaceful, then simultaneously the speech and body become peaceful. But if the mind is uncontrolled, then our words and actions are also out of control. Until we tame the mind, experiences of joy do not last more than a short time, no matter how many external supports we use. It is only by taming the mind that we can truly understand ourselves and others and find ultimate peace and joy.