^ Example from central African occurrence. A. R. Woolley, Alkaline Rocks and Carbonatites of the World: Africa, Geological Society of London (May 2001), p. 139 ISBN 1-86239-083-5
^
Kresten, Peter; Troll, Valentin R. (2018). "The Alnö Carbonatite Complex, Central Sweden". GeoGuide. doi:10.1007/978-3-319-90224-1. ISSN 2364-6497.