Upton, Brian G. J. “The Geology of Tugtutôq and Neighbouring Islands South Greenland, Part II. Nordmarkitic Syenites and Related Alkaline Rocks”. Meddelelser Om Grønland, vol. 170, no. 1, June 1964, pp. 1-61, https://tidsskrift.dk/meddrgroenland/article/view/160422.