1. L. L. Shishov, V. D. Tonkonogov, I. I. Lebedeva, and M. I. Gerasimova, Classification and Diagnostic System of Russian Soils (Oikumena, Smolensk, 2004) [in Russian].
2. Classification and Diagnostics of Soils of the Soviet Union (Kolos, Moscow, 1977) [in Russian].
3. E. A. Kornblyum, I. S. Mikhailov, N. A. Nogina, and V. O. Targulian, Basic Scales of the Properties of Morphological Soil Elements (Dokuchaev Soil Science Inst., Moscow, 1982) [in Russian].
4. Field Guide for Identification of Russian Soils (Dokuchaev Soil Science Inst., Moscow, 2008) [in Russian].
5. N. B. Khitrov, Genesis, Diagnostics, Properties, and Functioning of Clayey Swelling Soils of the Central Cis-Caucasus (Dokuchaev Soil Science Inst., Moscow, 2003) [in Russian].