- Author: Gottschalk Petter
- Language: Norwegian
- Year: 2000
- Author: Gottschalk Petter
- Language: English
- Year: 2018
- Author: Gottschalk Petter, Stanislas Perry
- Language: English
- Year: 2017
- Author: Gottschalk Petter
- Language: English
- Year: 2017
- Author: Petter Gottschalk Petter Gottschalk
- Language: English
- Year: 2006