MITCHELL, R.H. Accessory Rare Earth. Strontium, Barium and Zirconium Minerals in the Benfontein and Wesselton Calcite Kimberlites. International Kimberlite Conference: Extended Abstracts, [S. l.], v. 5, p. 292–294, 1991. DOI: 10.29173/ikc2544. Disponível em: https://ikcabstracts.com/index.php/ikc/article/view/2544. Acesso em: 25 apr. 2024.