Stenzel, H. B., Bernhard Kummel, Walter C. Sweet, Curt Teichert, and W. M. Furnish. 1964. “Part K, Mollusca 3, Ch. 2, P. 59-127”. Treatise on Invertebrate Paleontology, January. https://doi.org/10.17161/dt.v0i0.5258.