Vasilevitch, Roman, Evgeniy Lodygin, and Vasiliy Beznosikov. “Molecular-Mass Distribution of Tundra Soils Humic Substances from the European Northeast of Russia”. Biological Communications0, no. 4 (December 25, 2015): 103–111. Accessed October 27, 2020. https://biocomm.spbu.ru/article/view/692.