Pansky, Ben (1982), "Chapter 12: Fertilization", Review of MEDICAL EMBRYOLOGY, LifeMap Discovery, archived from the original on August 8, 2018, retrieved December 31, 2018
web.archive.org
Pansky, Ben (1982), "Chapter 12: Fertilization", Review of MEDICAL EMBRYOLOGY, LifeMap Discovery, archived from the original on August 8, 2018, retrieved December 31, 2018