Allsopp, H. L., C. B. Smith, J. W. Bristow, R. Brown, J. D. Kramers, and O. G. Garvie. 1986. “A Review of Radiometric Dating Methods Applicable to Kimberlites and Related Rocks”. International Kimberlite Conference: Extended Abstracts 4 (1):109-11. https://doi.org/10.29173/ikc1089.