- Author: Ulrich Hilpert
- Language: English
- Year: 2015
- Author: Ulrich Hilpert
- Language: English
- Year: 2015
- Author: Ulrich Hilpert Helen Lawton Smith
- Language: English
- Year: 2012
- Author: Ulrich Hilpert (auth.)
- Language: German
- Year: 1991
- Author: Ulrich Hilpert
- Language: English
- Year: 1991