Ref.: Ericksson, S.C. (1989) Phalaborwa: a saga of magmatism, metasomatism and miscibiolity. In: Carbonatites: Genesis and Evolution (K. Bell, editor). Unwin Hyman, London, U.K. (221-254).
http://www.edu.uni-klu.ac.at/~mmessner/sites/rsa/palabora/palabora.htm