Reimers, Eigil, and Sigurd Svela. “VIGILANCE BEHAVIOUR IN WILD AND SEMI-DOMESTIC REINDEER IN NORWAY”. Alces: A Journal Devoted to the Biology and Management of Moose 37, no. 2 (January 1, 2001): 303–313. Accessed September 30, 2023. https://www.alcesjournal.org/index.php/alces/article/view/583.