- Radio Free Europe/Radio Liberty, Inc - Research Institute12
- Bortstieber, Gertrud4
- Pallai, Péter4
- Hanák, Péter3
- Samizdat Archives3
- Soviet Red Archives3
- Nóvé, Béla2
- Open Media Research Institute2
- Analytic Research Department1
- Balkan Section1
- Balogh, Eva S.1
- British Broadcasting Corporation, Written Archive Centre1
- Bulgarian Unit1
- Communist International (Comintern)1
- Czechoslovak Unit1
- Fic, Victor M.1
- Fondation pour une entraide intellectuelle européenne, FEIE1
- Free Europe Committee, Inc1
- Great Britain, Foreign and Commonwealth Office1
- Hegedüs, András1