Kolesnikov, Sergey, Daria Moshchenko, Anna Kuzina, Kamil Kazeev, and Yuliya Akimenko. “Development of Regional Maximum Permissible Concentrations of Oil, Lead, Chromium, Nickel, and Copper in the Ordinary Black Soils of Central Ciscaucasia”. Amazonia Investiga 8, no. 24 (November 21, 2019): 38-44. Accessed April 24, 2024. https://amazoniainvestiga.info/index.php/amazonia/article/view/948.