1. L. N. Aleksandrova, Soil Organic Matter and Its Transformation (Nauka, Leningrad, 1980) [in Russian].
2. N. N. Bambalov, Organic Matter Budget of Peat Soils and Methods of Its Study (Nauka i Tekhnika, Minsk, 1984) [in Russian].
3. N. N. Bambalov, “Isolation of Lignin Preparations from Humified Materials and Their Properties,” Pochvovedenie, No. 5, 549–556 (2001) [Eur. Soil Sci. 34 (5), 484–491 (2001)].
4. B. A. Dospekhov, Procedure of Field Experiments (Moscow: Kolos, 1973) [in Russian].
5. M. M. Kononova, Soil Organic Matter (Akad. Nauk SSSR, Moscow, 1963) [in Russian].