R.H. Verschure, C. Maijer and P.A.M. Andriessen (1989) “Isotopic age determinations in South Norway: I. The Skar volcanic breccia, Greipstad, Vestagder”, Netherlands Journal of Geosciences, pp. 253-256. Available at: https://njgjournal.nl/index.php/njg/article/view/12901 (Accessed: 6April2026).