Simplify the following text for a Grade 9 native English-speaking person.
Original: He is also the founder and spiritual director of Rigpaâ '' an international network of over 100 Buddhist centres and groups in 23 countries around the worldâ '' and the author of the best-selling book The Tibetan Book of Living and Dying , which has been printed in 30 languages and 56 countries .
Simplified: He is the founder and spiritual leader of Rigpa , which is an international network of over 100 Buddhist centres and groups in 23 countries around the world . He is also the author of the best-selling book The Tibetan Book of Living and Dying , which has been printed in 30 languages and 56 countries .