- British Broadcasting Corporation, Written Archive Centre1
- Bykov, N.1
- Cianfarra, Camille Maximilian1
- Communist International (Comintern)1
- Czechoslovak Republic. Ministerstvo zahraničních věcí1
- Czereśniewski, Wawrzyniec1
- Dallin, David J.1
- Davies, Joseph Edward1
- Eppstein, John1
- Fredro, Aleksander1
- Great Britain, Foreign and Commonwealth Office1
- Hegedüs, András1
- Hámori, László1
- Juhász-Nagy, Sándor1
- Kalinin, M. I.1
- Kemény, István1
- Klug, Ignaz1
- Koestler, Arthur1
- Krasicki, Ignacy1
- Kutub-Zade, K.1