- Radio Free Europe/Radio Liberty, Inc - Research Institute7
- Bortstieber, Gertrud5
- Samizdat Archives3
- Geréb, Anna2
- Hanák, Péter2
- Analytic Research Department1
- Chiaureli, Mikhail1
- Communist International (Comintern)1
- Cornforth, Maurice Campbell1
- Gippius, Z. N.1
- Hegedüs, András1
- Heym, Stefan1
- Mochulʹski, Konstantin Vasilʹevich1
- Open Society Archives at Central European University1
- Pavelkin, Petr Artem'evich1
- Polish Unit of RFE/RL Research Institute; RFE/RL RI1
- Romanian Unit1
- Samizdat Archives of Radio Free Europe1
- Sedykh, Andrei1
- Shik, A.1