Berggren, W. A., M. F. Glaessner, Adolf Papp, A. R. Palmer, J. A. Van Couvering, A. W. Norris, A. H. Müller, et al. “Part A, Introduction, Complete Volume”. Treatise on Invertebrate Paleontology (January 1, 1979). Accessed May 3, 2024. https://journals.ku.edu/InvertebratePaleo/article/view/5534.