Rowell, Janice E., Robert G. White, and William E. Hauer. “Progesterone During the Breeding Season and Pregnancy in Female Muskoxen on Different Dietary Regimens”. Rangifer 17, no. 3 (February 1, 1997): 125–129. Accessed August 15, 2022. https://septentrio.uit.no/index.php/rangifer/article/view/1363.