Bratberg, Terje (2007). "Anker". In Henriksen, Petter (ed.). Store norske leksikon (بالنرويجية). Oslo: Kunnskapsforlaget. Archived from the original on 2019-05-12. Retrieved 2010-06-11.
Bratberg, Terje (2007). "Anker". In Henriksen, Petter (ed.). Store norske leksikon (بالنرويجية). Oslo: Kunnskapsforlaget. Archived from the original on 2019-05-12. Retrieved 2010-06-11.