Hess, Hans, A. N. Mironov, and M. Eléaume. “Part T, Echinodermata 2 (Revised), Vol. 3, Ch. 3, P. 160–225”. Treatise on Invertebrate Paleontology (January 1, 2011). Accessed April 27, 2024. https://journals.ku.edu/InvertebratePaleo/article/view/5393.