1. O. T. Vedina, Candidate’s Dissertation in Biology (Moscow, 1979).
2. Yu. N. Vodyanitskii, Chemistry and Mineralogy of Soil Iron (Moscow, 2003) [in Russian].
3. K. E. Ginzburg, Phosphorus in the Main Soil Types of the USSR (Nauka, Moscow, 1981), p. 241 [in Russian].
4. K. E. Ginzburg and L. S. Lebedeva, “Procedure of Determining Mineral Phosphorus in Soils,” Agrokhimiya, No. 1 (1971).
5. S. V. Zonn, Iron in Soils (Nauka, Moscow, 1983) [in Russian].