Kjell Billstrom, Goran Aberg, and Bjorn Ohlander. “Isotopic and Geochemical Data of the Pingstaberg Mo-Bearing Granite in Bergslagen, South Central Sweden”. Netherlands Journal of Geosciences (January 1, 1988): 255-263. Accessed April 6, 2026. https://njgjournal.nl/index.php/njg/article/view/13067.