W. Gotje, M.C.A. Van Wayjen, and B. Van Geel. “A Palynological Study of a Holocene Deposit from Grand-Bongard (Hautes-Fagnes, Belgium)”. Netherlands Journal of Geosciences (January 1, 1990): 227-241. Accessed March 31, 2026. https://njgjournal.nl/index.php/njg/article/view/12866.