Are these both correct:
1-I wondered if some books by Tolstoy were available or if they were all sold out.
2-I wondered if some books by Tolstoy were available: War and Peace, Anna Karina, The Resurrection and The Death of Ivan Illich.
If you don't care which ones, I'd use "any" for the first.
I'm not a teacher, but I write for a living. Please don't ask me about 2nd conditionals, but I'm a safe bet for what reads well in (American) English.