1. Agroecology, Ed. by V. A. Chemikov and A. I. Chekeres (Kolos, Moscow, 2000) [in Russian].
2. A. E. Vozbutskaya, Soil Chemistry (Vysshaya Shkola, Moscow, 1968) [in Russian].
3. A. Kabata-Pendias, “Problems in the Current Biogeochemistry of Microelements,” Ros. Khim. Zh. (Zh. Ros. Khim. O-va D. I. Mendeleeva) 49(3), 15–19 (2005).
4. A. Kabata-Pendias and H. Pendias, Trace Elements in Soils and Plants (CRC, Boca Raton, 1985).
5. D. V. Ladonin, “The Effect of Iron and Clay Minerals on the Adsorption of Copper, Zinc, Lead, and Cadmium in the Nodular Horizon of Podzolic Soil,” Pochvovedenie, No. 10, 1197–1206 (2003) [Eur. Soil Sci. 36 (10), 1065–1073 (2003)].