Larsen 1950, стр. 110. Larsen, Karen (1950) [1948]. A History of Norway. The American-Scandinavian Foundation, Princeton University Press. стр. 110. OCLC257284542.
Larsen 1950, стр. 113 Larsen, Karen (1950) [1948]. A History of Norway. The American-Scandinavian Foundation, Princeton University Press. стр. 110. OCLC257284542.
Hjalmar Hjorth Boyesen (1889). The Story of Norway, The Story of the Nations. New York: Putnam. стр. 237. OCLC1536116.
Gjerset, Knut (1915). History of the Norwegian People. 1. New York: Macmillan. стр. 279. OCLC1674570.