^ abColton, Frank B.; Nysted, Leonard N.; Riegel, Byron; Raymond, Albert L (1957). "17-Alkyl-19-nortestosterones". Journal of the American Chemical Society. 79 (5): 1123–1127. doi:10.1021/ja01562a028. ISSN0002-7863.
^ abMIYAKE T, PINCUS G (1958). "Progestational activity of certain 19-norsteroids and progesterone derivatives". Endocrinology. 63 (6): 816–24. doi:10.1210/endo-63-6-816. PMID13609555.
^McRobb L, Handelsman DJ, Kazlauskas R, Wilkinson S, McLeod MD, Heather AK (2008). "Structure-activity relationships of synthetic progestins in a yeast-based in vitro androgen bioassay". J. Steroid Biochem. Mol. Biol. 110 (1–2): 39–47. doi:10.1016/j.jsbmb.2007.10.008. PMID18395441.
^F. J. Zeelen (1990). Medicinal chemistry of steroids. Elsevier Science Limited. pp. 108–109. ISBN978-0-444-88727-6. Other examples are allylestrenol (42), a pro-drug converted to the 3-keto analogue (43), which is used in the treatment of threatened abortion [78,79] and altrenogest (44), used in sows and mares to suppress ovulation and estrus behaviour [80]. [...] Progestins with a 17a-allyl side chain: (42) allylestrenol, (43), (44) altrenogest.