Glaessner, M. F., Hoffman, R. L., Newman, W. A., Hahn, G., Zullo, V. A., & Rolfe, W. D. I. (1969). Part R, Arthropoda 4, vol. 1 & 2, ch. 5, p. 567-629. Treatise on Invertebrate Paleontology. https://doi.org/10.17161/dt.v0i0.5630