Lecompte, M., Moore, R. C., Hill, D., Harrington, H. J., Montanaro-Gallitelli, E., Bayer, F. M., & Wells, J. W. (1956). Part F, Coelenterata, Ch. 2, p. 107-231. Treatise on Invertebrate Paleontology. https://doi.org/10.17161/dt.v0i0.5537