1. Orlov, D.S., Sorosovskii Obrazovat. Zh., 1997, no. 2, p. 56.
2. Orlov, D.S., Pochvovedenie, 1998, no. 9, p. 1049.
3. Perminova, I.V. and Zhilin, D.M., in Green Chemistry in Russia, Lunin, V.V., Tundo, P., and Lokteva, E.S., Eds., Moscow: Mosk. Gos. Univ., 2004, p. 146.
4. Gostishcheva, M.V., Extended Abstract of Cand. Sci. (Chem.) Dissertation, Perm State Pharm. Acad., Perm, 2008.
5. Lishtvan, I.I., Kruglitskii, N.N., and Tretinnik, V.Yu., Fizikokhimicheskaya mekhanika guminovykh veshchestv (Physicochemical Mechanics of Humic Substances), Minsk: Nauka i Tekhnika, 1976.