Kresten Nielsen, Jesper, and Mikael Pedersen. “Hydrothermal Activity in the Upper Permian Ravnefjeld Formation of Central East Greenland – a Study of Sulphide Morphotypes”. Geology of Greenland Survey Bulletin 180 (December 31, 1998): 81–87. Accessed May 1, 2024. https://geusjournals.org/index.php/ggub/article/view/6502.