- Radio Free Europe/Radio Liberty, Inc - Research Institute8
- Bortstieber, Gertrud4
- Pallai, Péter4
- Hanák, Péter3
- Samizdat Archives3
- Nóvé, Béla2
- United States. Department of State2
- American Federation of Labor1
- Ascoli, Max1
- Balkan Section1
- Balogh, Eva S.1
- Balzak, S. S.1
- Blau, Joseph L.1
- British Broadcasting Corporation, Written Archive Centre1
- Bulgarian Unit1
- Clissold, Stephen1
- Cole, George Douglas Howard1
- Communist International (Comintern)1
- Counts, George S.1
- Dallin, David J.1