ed to detect censorship. (A) Usage frequency of “Marc Chagall” in German (red) as compared to English (blue). (B) Suppression of Leon Trotsky (blue), Grigory Zinoviev (green), and Lev Kamenev (red) in Russian texts, with noteworthy events indicated: Trotsky’s assassination (blue arrow), Zinoviev and Kamenev execute