E. I. Semenov, H. Sørensen, M. S. Bessmertnaja, and L. E. Novorossova, “2. Chalcothallite- a new Sulphide of Copper and Thallium from Ilímaussaq Intrusion, South Greenland”., Meddr Grønland, vol. 181, no. 5, pp. 13–37, Oct. 1967.