^"Hazardous Substances Data Bank" data were obtained from the National Library of Medicine (US). Retrieved from SciFinder. [2022-3-15].
^Völz, Hans G. et al. "Pigments, Inorganic" in Ullmann's Encyclopedia of Industrial Chemistry, 2006 Wiley-VCH, Weinheim. doi:10.1002/14356007.a20_243.pub2.