Helmstaedt, H., and R. Harrap. “Tectonic Aspects of the Kimberlite - Diamond - Upper-Mantle-Sample Connection: Does a Coherent Model Evolve?”. International Kimberlite Conference: Extended Abstracts, vol. 7, no. 1, Apr. 1998, pp. 331-5, doi:10.29173/ikc2726.