E.D. van Riessen, and N. Vandenberghe. “An Early Oligocene Oil Seepage at the Southern Rim of the North Sea Basin, Near Leuven (Belgium)”. Netherlands Journal of Geosciences 74 (January 1, 1995): 301-312. Accessed April 2, 2026. https://njgjournal.nl/index.php/njg/article/view/12437.