R.W.J.M. van der Ham, J.W.M. Jagt, and H.J. Janssens. “Leymeriaster Campestris, a New Early Campanian Hemiasterid Echinoid from Southern Limburg, the Netherlands”. Netherlands Journal of Geosciences 90 (November 1, 2011): 179 - 185. Accessed March 26, 2026. https://njgjournal.nl/index.php/njg/article/view/12049.