You can find and download books about Spetsnaz (special forces) for free on several digital library platforms and archive sites. Depending on whether you are looking for non-fiction historical accounts or action fiction, the following sources are your best bet:

: A well-known community-driven "pirate" library that offers a wide range of free books, though its accessibility can vary by region. Notable Titles Available Online Флибуста - Википедия

: Primarily focuses on older literature where copyrights have expired. While it may not have modern tactical manuals, it contains historical military accounts like " Fighting Without a War " (Northern Russia intervention).

: This is a massive resource for historical and non-fiction books. You can find titles like " Spetsnaz: Russia's Special Forces " by Mark Galeotti or " Spetsnaz " by Viktor Suvorov for free borrowing or streaming.

: A popular Russian-language site where you can download books in FB2 and other formats specifically under the "Military Prose" genre.

Флибу́ста (от слова флибустьер) — пиратская бесплатная некоммерческая онлайн-библиотека. Википедия