N. Keutgen. 1996. “Belemnella (Belemnella) Cf. Praearkhangelskii Naidin, 1964 from the Vijlen Member at Altembroeck (NE Belgium, Early Maastrichtian) ”. Netherlands Journal of Geosciences 75 (January):341-47. https://njgjournal.nl/index.php/njg/article/view/12384.