- Author: Joachim von zur Gathen Jürgen Gerhard
- Language: English
- Year: 2013
- Author: Joachim von zur Gathen Jürgen Gerhard
- Language: English
- Year: 2003
- Author: Joachim von zur Gathen Jürgen Gerhard
- Language: English
- Year: 2003
- Author: Joachim von zur Gathen Jürgen Gerhard
- Language: English
- Year: 2003
- Author: Joachim von zur Gathen Jürgen Gerhard
- Language: English
- Year: 1999