Allaye-ChanA. C., WhiteR. G., HollemanD. F., and RussellD. E. “Seasonal Concentrations of Cesium-137 in Rumen Content, Skeletal Muscles and Feces of Caribou from the Porcupine Herd: Lichen Ingestion Rates and Implications for Human Consumption”. Rangifer 10, no. 3 (September 1, 1990): 17-24. Accessed January 28, 2020. https://septentrio.uit.no/index.php/rangifer/article/view/816.