1. N. A. Artemkina, T. T. Gorbacheva, and N. V. Lukina, “Low-molecular-weight organic acids in soil water of forests of the Kola Peninsula,” Lesovedenie, No. 6, 37–44 (2008).
2. E. I. Karavanova, “Dissolved organic matter: fractional composition and sorbability by the soil solid phase (review of literature),” Eurasian Soil Sci. 46, 833–844 (2013).
3. I. S. Kaurichev and E. M. Nozdrunova, “Migration and qualitative composition of water-soluble organic matter in forest-meadow soils,” Izv. Timiryazevsk. S-kh. Akad., No. 5, 91–106 (1962).
4. I. S. Kaurichev, T. N. Ivanova, and E. M. Nozdrunova, “The content of low-molecular organic acids in water-soluble organic soil matter,” Pochvovedenie, No. 3, 27–35 (1963).
5. I. S. Kaurichev and L. N. Frolova, “Individual water-soluble organic matter in forest litter,” Dokl. Timiryazevsk. S-kh. Akad., No. 115, 19–24 (1965).