Gotaas, Geir, and Nicholas J.C. Tyler. “Faeces Is a Reliable Source of Body Water for Measuring Tritium in Reindeer in Summer and in Winter”. Rangifer 15, no. 2 (January 1, 1995): 63–70. Accessed August 7, 2026. https://septentrio.uit.no/index.php/rangifer/article/view/1168.