There are no "official/proper transliterations" other than the ones you create for your institution, which is probably an academic library because I've not heard of anyone else caring about consistent transliteration. I've seen the same Greek and Russian names transcribed in all sorts of ways in government documents. Fortunately, all government documents have some kind of a number on them. That's what you use for your database key. Names aren't unique in any case, even with the extra variation introduced by whimsical transcription.