Start with high-confidence soviet era russia books, then narrow by subgenre or adjacent topics.
The Gulag Archipelago [volume 1]
Aleksandr I. Solzhenitsyn, Aleksandr Solzhenitsyn
The Gulag Archipelago
Aleksandr Solzhenitsyn, Thomas P. Whitney
The Decembrist Myth in Russian Culture
L. Trigos, Ludmilla A. Trigos
April 1917
Aleksandr Solzhenitsyn, Clare Kitson
The CIA Book Club
Charlie English
KGB Literati
Kovacevic, Filip Kovacevic
Odyssey Moscow
Michael Calvey
The Lost Empire of Emanuel Nobel
Douglas Brunt