Helle, T., S.-S. Kilpelä, and P. Aikio. “Lichen ranges, animal densities and production in Finnish reindeer management”. Rangifer 10, no. 3 (September 1, 1990): 115–121. Accessed April 19, 2024. https://septentrio.uit.no/index.php/rangifer/article/view/840.