^"Christian IV | Scandinavian king". Encyclopedia Britannica. Retrieved 19 November 2019.
^Bang, A. Chr. (1912). Den norske kirkes historie (in Norwegian). Kristiania and Copenhagen: Gyldendal. p. 361.
^"Post Danmarks Historie 1624- 2002" (in Danish). Post Danmark. Retrieved 2012-11-01.
^Wasberg, Gunnar Christie. "Cort Aslakssøn". In Helle, Knut (ed.). Norsk biografisk leksikon (in Norwegian). Oslo: Kunnskapsforlaget. Retrieved 29 October 2012.