I hope I found the right stackexchange site for this question.
I'm in the process of translating a book (scientific publication) for private use. If I ever decide to publish it, what is the procedure - who is the right person to ask for publishing rights and translation approval?
Update (previously posted as a comment):
Two of three authors are deceased, and I still need to find out what is the situation with the third one. I'm translating from a Russian translation of the book (due to the unavailability of the original).
If all three authors show up to be deceased - should I contact the original publisher(s) (since it was a joint publication by two companies) or the publisher of the version I'm translating (since one (the Poles) are holding the general, and the other (the Russians) are holding the Russian translation rights)?
Furthermore, the Russian publisher went out of business (Mir Moscow).