1. Reproductive efficiency of bulls in natural service: effects of male to female ratio and single‐ vs multiple‐sire breeding groups;Rupp G.;J. Am. Vet. Med. Assoc.,1977
2. Corpus cavernosum penis pressure and external penile muscle activity during erection in the goat;Beckett S.;Biol. Reprod.,1972
3. Blood pressure within the corpus cavernosum penis of the bull;Lewis J.;J. Reprod. Fertil.,1968