Smirnov, G.I., A.D. Kharkiv, and N.N. Zinchuk. “On the Problem of Vertical Zoning of Kimberlite Bodies (on the Example of Lesotho)”. International Kimberlite Conference: Extended Abstracts 5 (February 1, 1991): 551–552. Accessed April 5, 2025. https://ikcabstracts.com/index.php/ikc/article/view/2425.