- Author: Geo Widengren, Rosmarie Elgnowski
- Language: German
- Year: 1969
- Author: Arne Furumark Sture Lagercrantz Israel Ruong Dag Strömbäck Geo Widengren (eds.)
- Language: English
- Year: 1956
- Author: Geo Widengren
- Language: English
- Year: 1951
- Author: Geo Widengren
- Language: Polish
- Year: 2008
- Author: Geo Widengren, David Hellholm
- Language: English
- Year: 1977
- Author: Geo Widengren
- Language: Spanish
- Year: 1976
- Author: Geo Widengren
- Language: English
- Year: 1950
- Author: Geo Widengren (auth.)
- Language: German
- Year: 1960