^"Christian IX | king of Denmark". Encyclopedia Britannica. Retrieved 17 June 2019.
^Government of Denmark and Government of Portugal (14 December 1896). "Declaration supplementing provisionally the Declaration of December 14th, 1896, regarding Commercial and Maritime Relations between the two Countries" (PDF). United Nations Treaty Series. United Nations. Archived from the original (PDF) on 28 July 2011. Retrieved 21 February 2011.