This dictionary by Y.N. Roerich was edited posthumously by Parfionovich and Dylykova, as a valuable guide to Classical Tibetan. It is a vade mecum to translate Tibetan historical and philosophical texts. It has new words which are not found in the dictionaries of Jaschke and S.C. Das. Roerich could not find words and expressions while translating the Blue Annals into English. He had to access traditional scholars like Gendun Chomphel from Tibet and Sanggye from Buryatia who interpreted the Annals in terms of language and its terse style that presupposes traditional learning. This dictionary is to facilitate the understanding of classical vocabulary. The entries are precise and lead the reader to the central concept of the word. It is an outcome of the life-long experience of Y.N. Roerich, supplemented by the two editors who had access to the Buryat heritage of Tibetan. This compact edition in two bindings will be a ready reference for all Tibetanists. The original edition was a rare even when published in the 1980s.