[1]
A. S. Povarennykh, A. M. Platonov, A. N. Tarashchan, and V. P. Belichenko, “The colour and luminiscence of Tugtupite (Beryllosodalite) from Ilímaussaq, South Greenland”., Meddr Grønland, vol. 181, no. 14, p. 12 pp., Jun. 1971.