- Author: Meldon C. Wass
- Language: English
- Year: 1964
- Author: Dietrich von Hildebrand
- Language: English
- Year: 1963
- Author: Dietrich von Hildebrand
- Language: English
- Year: 1977
- Author: Dietrich von Hildebrand
- Language: English
- Year: 1971
- Author: Gerhard Lohfink
- Language: English
- Year: 1976
- Author: Lucy Rooney Robert Faricy
- Language: English
- Year: 1985
- Author: Lucan Freppert
- Language: English
- Year: 1988