Kolesnikov, S.I., Moshchenko, D.I., Kuzina, A.A., Kazeev, K.S. y Akimenko, Y.V. 2019. Development of Regional Maximum Permissible Concentrations of Oil, Lead, Chromium, Nickel, and Copper in the Ordinary Black Soils of Central Ciscaucasia. Amazonia Investiga. 8, 24 (nov. 2019), 38–44.