Williams, Alwyn, D. I. MacKinnon, and C. H. C. Brunton. “Part H, Brachiopoda (Revised), Vol. 1, Ch. 4, P. 321–440”. Treatise on Invertebrate Paleontology (January 1, 1997). Accessed April 28, 2024. https://journals.ku.edu/InvertebratePaleo/article/view/5556.