Callaghan, T. V., N. J. C. Tyler, and B. Carlsson. “Fluctuation in plant growth and in reindeer populations in Svalbard”. Rangifer 10, no. 3 (September 1, 1990): 157–158. Accessed June 7, 2025. https://new.eludamos.org/index.php/rangifer/article/view/848.