Zaderatsky was a pianist and composer who ended up in the Gulag in the later 1930s, during which time he reportedly use telegraph paper and a pencil to compose a cycle of 24 preludes and fugues for piano. The cycle has only come to light within the last ten years and has only gotten a premiere and a few performances within the last five, it seems.
There are recordings of this cycle but the score is not so easy to get ahold of, at least in Western contexts.
I know for sure you can find it at Theodore Front music, though.
Brace yourself for the sticker price and be willing to read Russian or put up with not being able to read it.
This is one of the more compelling contrapuntal cycles I've heard in the last ten years. It's got a Russian futurist vibe to it although Zaderatsky was, from what I've managed to read about him of Ukrainian/Polish descent.
This video linked to above features the prelude and fugue in f sharp minor (starts 00:12)and then the one in E major (starts 7:30).
Hoping to write more about this cycle later this year or ... given how belated all my writing seems to be this year and last it may be next year before I feel up to writing about the Zaderatsky cycle.