Garvie, C. L., J. L. Goedert, and A. W. Janssen. “Paleogene and Late Cretaceous Pteropoda (Mollusca, Gastropoda, Heterobranchia) from North America”. Zootaxa, vol. 4782, no. 1, May 2020, pp. 1–115, doi:10.11646/zootaxa.4782.1.1.