The Russian original of the present work was posthumously
published in 1962 in the revived Bibliotheca Buddhica series and
edited by G. N. Roerich.
On two points, the English publication differs from the
Russian original. First, in the Russian original the notes and
references are given at the end of the book while in the present
translation these are rearranged page-wise. Secondly, all the
Tibetan words are given here in Roman transliteration and this
based on the principles followed in the Tibetan-English
Dictionary by S. C. Das.
To Dr. I. D. Serebryakov of the Institute of the Peoples of
Asia (now Institute of Oriental Studies), Academy of Sciences,
USSR, we are indebted for the copy of the Russian original
and for very much else besides.