1. The perineum of the mare;Habel;Cornell Vet,1953
2. Equine Urogenital System—Female Genitalia;Sisson,1975
3. Observations on the length and angle of declination of the vulva and its relation to fertility in the mare;Pascoe;J Reprod Fertil Suppl,1979
4. Reproductive Organs of the Mare;Kainer,1993
5. Examination of the Vulva, Vestibule, Vagina, and Cervix;Ley,1999