Apart from the (auto-)biographical books written in English and some of the English genealogical sources, my main source for names is the Moscow Address Books. All of those are in Russian, which leads to the following difficulties:
- The Russian transliteration sometimes makes the surnames unrecognisable and therefore not very easily transliterated back into English. You have to guess a lot and it doesn't always work.
- Practically all of the British people, especially those who lived in Russia on a permanent basis, acquired the Russian equivalents of the English names. Thus, William would become Vassily; John - Ivan; George - either Egor or Georg, Jane - Evgenia, etc.