- Bortstieber, Gertrud8
- Radio Free Europe/Radio Liberty, Inc - Research Institute5
- Hanák, Péter3
- Nóvé, Béla2
- Samizdat Archives2
- Balkan Section1
- Buber-Neumann, Margarete1
- Bulgarian Unit1
- Communist International (Comintern)1
- Curtius, Ernst Robert1
- Fischer, Kurt J.1
- Free Europe Committee, Inc1
- Hegedüs, András1
- Heimbürger, Boris1
- Kautsky, Karl1
- Löwenthal, Richard1
- Magos-Gimes, Judit1
- Marx, Karl1
- Mihalovics, Sigismund1
- Open Society Archives at Central European University1