Libgen absolutely does have anti-Putin books in English. But I don't know about Russian. For instance, I found: Blowing Up Russia: The Secret Plot to Bring B

Libgen absolutely does have anti-Putin books in English. But I don't know about Russian. For instance, I found: Blowing Up Russia: The Secret Plot to Bring Back KGB Terror by Alexander Litvinenko (the guy Putin murdered with Polonium) Winter Is Coming: Why Vladimir Putin and the Enemies of the Free World Must Be Stopped by Garry Kasparov Freezing Order : A True Story of Money Laundering, Murder, and Surviving Vladimir Putin's Wrath by Bill Browder Putin's labyrinth: spies, murder, and the dark heart of the new Russia by Steve Levine Mr. Putin by Fiona Hill