- Author: Karl Marx, Transcribed and edited by Lawrence Krader
- Language: English
- Year: 1974
- Author: Deuwe G. Jongmans & Peter Claus Wolfgang Gutkind
- Language: English
- Year: 1967
- Author: Jaap Mansfeld
- Language: English
- Year: 1971
- Author: Cornelia J. de Vogel
- Language: English
- Year: 1966
- Author: David T. Runia
- Language: English
- Year: 1993
- Author: Jaap Mansfeld
- Language: English
- Year: 1971
- Author: Petrus Abaelardus
- Language: Latin
- Year: 1956
- Author: Petrus Abaelardus
- Language: Latin
- Year: 1956
- Author: Björn Gustavsen
- Language: English
- Year: 1992