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, ངོ་ section, volume གོ་, beginning at leaf 165. The Tibetan translator describes it as the second volume but I cannot say whether the remainder of the work has been preserved in Tibetan--the Sanscrit original is apparently lost.