Friend, P. F., Alexander-Marrack, P. D., Nicholson, J., & Yeats, A. K. (1976). Devonian Sediments of East Greenland I. Introduction, Classification of Sequences, Petrographic Notes. Meddelelser Om Grønland, 206(1), 56 pp. Hentet fra https://tidsskrift.dk/meddrgroenland/article/view/141445