John W.M. Jagt, Anne S. Schulp, and Douwe Th. de Graaf. “The 150th Anniversary of the Maastrichtian Stage - a Celebratory Conference: Introduction”. Netherlands Journal of Geosciences 82 (August 1, 2003): 223-224. Accessed March 30, 2026. https://njgjournal.nl/index.php/njg/article/view/11528.