Nagarjuna 
The Tree of Wisdom [EPUB ebook] 

The She-rab Dong-bu (Tree of Wisdom) is a metrical translation in Tibetan of a Sanscrit ethical work entitled Prajnya Danda, written by Nagarjuna who flourished in the fourth century of the Buddhist era (about 100 B.C.), The Tibetan version was probably made about the 11th century of our era but the exact date has not been determined. It is included in the Ten-gyur, beginning at leaf 165.