O'Brien, Hugh E., Anthony J. Irving, and I. S. McCallum. “Evolution of Minette, Lamproite and Mafic Phonolite Magmas in the Highwood Mountains Province, Montana, USA: Geochemical and Mineralogical Evidence”. International Kimberlite Conference: Extended Abstracts 4, no. 1 (September 19, 1986): 199–201. Accessed December 4, 2024. https://ikcabstracts.com/index.php/ikc/article/view/1117.