1. SimpsonJ.L. (1985). Relationship between congenital anomalies and contraception.Adv. Contracept.,1, 3–30
2. SimpsonJ.L. (1984). Mutagenicity and teratogenicity of injectable and implantable progestins: probable lack of effect. In: G.I.Zatuchni, A.Goldsmith, J.D.Shelton, J.J.Sciarra, eds.,Long Acting Contraception Delivery Systems, Lippincott, Philadelphia, pp. 334–361
3. World Health Organization (WHO) Technical Report Series;World Health Organization,1981
4. SimpsonJ.L. (1978). Genetic consequences of aging sperm or aging ova: animal studies and relevance to humans. In: J.J.Sciarra, G.I.Zatuchni, J.J.Speidel, eds.,Risks, Benefits and Controversies in Fertility Control, Harper and Row, Hagerstown, pp. 506–517
5. GrayR.H. and KambicR.T. (1988). Epidemiological studies of natural family planning.Hum. Reprod.,3, 693–698