Williams, Alwyn, C. C. Emig, M. C. Rhodes, M. A. James, and Sarah Mackay. 1997. “Part H, Brachiopoda (Revised), Vol. 1, Ch. 1, P. 1–188”. Treatise on Invertebrate Paleontology, January. https://doi.org/10.17161/dt.v0i0.5553.