1. Chenoweth WL (1978) Uranium in western Colorado. US Energy Research and Development Administration report #TM-199, p 11
2. Chenoweth WL (1993) Historical review of carnotite mining and processing in southwestern Colorado. Report for US Bureau of Land Management, p 33
3. O’Connell DT (1939) The black dye of the Navajos. Science 90:272
4. Friedel C, Cumenge E (1899) Sur un nouveau minerai d’urane. Bull French Mineralog Soc 22(1–2):26–29
5. Tyler PM (1930) Radium. US Bureau of Mines Information Circular 6312, p 55