Skinner, E.M.W., et al. “The Petrography, Tectonic Setting and Emplacement Ages of Kimberlites in the South Western Border Region of the Kaapvaal Craton, Prieska Area, RSA”. International Kimberlite Conference: Extended Abstracts, vol. 5, Feb. 1991, pp. 373-5, doi:10.29173/ikc2574.