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 November 21, 2024. https://journals.ku.edu/InvertebratePaleo/article/view/5592.