Gingerich 1992, p. 73 Gingerich, P. D. (1992). "Marine Mammals (Cetacean and Sirenia) from the Eocene of Gebel Mokattam and Fayum, Egypt: Stratigraphy, Age, and Paleoenvironments". University of Michigan Papers on Paleontology. 30: 1–84. hdl:2027.42/48630. OCLC26941847.
Gingerich 1992, p. 73 Gingerich, P. D. (1992). "Marine Mammals (Cetacean and Sirenia) from the Eocene of Gebel Mokattam and Fayum, Egypt: Stratigraphy, Age, and Paleoenvironments". University of Michigan Papers on Paleontology. 30: 1–84. hdl:2027.42/48630. OCLC26941847.