1. Agrochemical Methods of Soil Examination (Nauka, Moscow, 1975) [in Russian].
2. A. F. Vadyunina and Z. A. Korchagina, Methods of Studying Soil Physical Properties (Agropromizdat, Moscow, 1985) [in Russian].
3. B. M. Kogut, “Principles and Methods of Assessing the Content of Labile Organic Matter in Plowed Soils,” Pochvovedenie, No. 3, 308–316 (2003) [Eur. Soil Sci. 36 (3), 283–291 (2003)].
4. Yu. A. Kokotov, P. P. Zolotarev, and G. E. El’kin, Theoretical Principles of Ion Exchange: Complex Ion-Exchange Systems (Khimiya, Leningrad, 1986) [in Russian].
5. N. E. Kosheleva, N. S. Kasimov, and O. A. Samonova, “Regression Models for the Behavior of Heavy Metals in Soils of the Smolensk-Moscow Upland,” Pochvovedenie, No. 8, 954–966 (2002) [Eur. Soil Sci. 35 (8), 845–856 (2002)].