Williams, Alwyn, M. G. Bassett, L. E. Popov, S. J. Carlson, and L. R. M. Cocks. “Part H, Brachiopoda (Revised), Vol. 2 & 3, Ch. 2, P. 158–349”. Treatise on Invertebrate Paleontology (January 1, 2000). Accessed May 6, 2024. https://journals.ku.edu/InvertebratePaleo/article/view/5207.