Soveri, T., E. Helynranta, M. Nieminen, E. Yliselä, and L. A. Lindberg. “Histological changes in rumen epithelium of reindeer calves during the winter season”. Rangifer, vol. 10, no. 3, Sept. 1990, p. 397, doi:10.7557/2.10.3.886.