- Author: Bruce A. Watson (auth.)
- Language: German
- Year: 1961
- Author: Derrick G. Kourie Bruce W. Watson (auth.)
- Language: English
- Year: 2012
- Author: Derrick G. Kourie Bruce W. Watson (auth.)
- Language: English
- Year: 2012
- Author: Derrick G. Kourie Bruce W. Watson (auth.)
- Language: English
- Year: 2012