Herman, J. (1984)
Additions to the Eocene (and Oligocene) fauna of Belgium. 7. Discovery of Gymnura teeth in Ypresian, Paniselian and Rupelian strata. Tertiary Research, 6(2): 47–54, 2 fig., 2 pl.
van den Eeckhaut, G. & de Schutter, P.J. (2009)
The Elasmobranch Fauna of the Lede Sand Formation at Oosterzele (Lutetian, Middle Eocene of Belgium). Palaeofocus, 1: 1–57, 2 fig., 2 tab., 22 pl.