LorenzV., KurszlaukisS., StachelT., BreyG., StanistreetI.G., and FranzL. “Volcanology of the Diatreme-Rich Carbonatitic Gross Brukkaros Volcanic Field and of the Nearby Gibeon Kimberlite Province, Namibia”. International Kimberlite Conference: Extended Abstracts 6, no. 1 (September 19, 1995): 333-335. Accessed July 8, 2020. http://ikcabstracts.com/index.php/ikc/article/view/1883.