^Geil RG, Lamar JK (September 1977). "FDA studies of estrogen, progestogens, and estrogen/progestogen combinations in the dog and monkey". Journal of Toxicology and Environmental Health. 3 (1–2): 179–93. Bibcode:1977JTEH....3..179G. doi:10.1080/15287397709529557. PMID411941.
^Jacobs AC, Hatfield KP (March 2013). "History of chronic toxicity and animal carcinogenicity studies for pharmaceuticals". Veterinary Pathology. 50 (2): 324–33. doi:10.1177/0300985812450727. PMID22700852. S2CID22367595.