Cox, L. R., T. Soot-Ryen, C. C. Brasnson, H. B. Stenzel, Aurèle LaRocque, A. Myra Keen, H. S. Puri, et al. “Part N, Mollusca 6, Vol. 2, Ch. 5, P. 491–690”. Treatise on Invertebrate Paleontology (January 1, 1969). Accessed July 22, 2024. https://journals.ku.edu/InvertebratePaleo/article/view/5592.