- Author: Gustav A. Wetter
- Language: English
- Year: 1958
- Author: Gustav Andreas Wetter SJ
- Language: Italian
- Year: 1948
- Author: Gustav Andreas Wetter SJ
- Language: Italian
- Year: 1948
- Author: Gustav A. Wetter
- Language: English
- Year: 1958
- Author: Gustav A. Wetter
- Language: English
- Year: 1958