1. B. P. Akhtyrtsev and V. D. Solovichenko, The Soil Cover of Belgorod Oblast: Patterns, Zonation, and Rational Use (Voronezh State Univ., Voronezh, 1984) [in Russian].
2. E. A. Afanas’eva, Chernozems of the Central Russian Upland (Nauka, Moscow, 1966) [in Russian].
3. L. S. Berg, Climate and Life (Ogiz-Geografgiz, Moscow, 1947) [in Russian].
4. A. N. Gennadiev, Soils and Time: Models of Development (Moscow State Univ., Moscow, 1990), pp. 136–137.
5. V. V. Gertsyk and A. A. Rode, “The elements of moisture balance in virgin chernozems in the steppe and oak forest,” Pochvovedenie, No. 7, 77–86 (1978).