1997, Geochemistry and mineralogy of soils eaten by humans

S. Aufreiter,R. G. V. Hancock,W. C. Mahaney,A. Stambolic-Robb &K. Sanmugadas
International Journal of Food Sciences and Nutrition
Volume 48, 1997 - Issue 5

https://www.tandfonline.com/doi/abs/10.3109/09637489709028575