1. A. Ya. Antykov and A. Ya. Stomorev, Soils of the Stavropol Region and Their Fertility (Stavropol, 1970) [in Russian].
2. E. V. Arinushkina, Handbook on the Chemical Analysis of Soils (Mosk. Gos. Univ., Moscow, 1970) [in Russian].
3. R. Kh. Aidinyan, M. S. Ivanova, and T. G. Solov’eva, Methods for the Extraction and Determination of Different Sulfur Forms in Soils and Plants (Guidelines) (Moscow, 1975) [in Russian].
4. V. A. Grinenko and M. V. Ivanov, “The Main Reactions of the Global Biogeochemical Sulfur Cycle,” in Global Biogeochemical Sulfur Cycle (Nauka, Moscow, 1983), pp. 12–32 [in Russian].
5. M. V. Ivanov, V. A. Grinenko, and A. L. Rabinovich, “Sulfur Flux from the Continents to the Ocean,” in Global Biogeochemical Sulfur Cycle (Nauka, Moscow, 1983), pp. 281–298 [in Russian].