Some older editions may be found on community-driven digital archives like Maxim Moshkow's Library (Lib.ru).
Sto let tomu vperyod (One Hundred Years Ahead) Author: Kir Bulychev (pseudonym of Igor Mozheyko)
Platforms like LitRes or MyBook offer the ebook and audiobook for purchase or subscription.
Because the author passed away in 2003, his works are often protected by copyright, though they are widely available across major digital platforms:
Part of the Alice's Adventures (Priklyucheniya Alisy) cycle.

