Allaye-Chan, A.C., White, R.G., Holleman, D.F. and Russell, D.E. 1990. 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, 3 (Sep. 1990), 17–24. DOI:https://doi.org/10.7557/2.10.3.816.