1. Bazilevich, N.I., Grebenshchikov, O.S., and Tishkov, A.A., Geograficheskie zakonomernosti struktury i funktsionirovaniya ekosistem (Ecosystems Structure and Functioning: Geographical Regularities), Moscow, 1986.
2. Bogatyrev, L.G., Classification of forest floors, Pochvovedenie, 1990, no. 3.
3. Bogatyrev, L.G., Demin, V.V., Matyshak, G.V., et al., Some theoretical aspects of forest floors research, Lesovedenie, 2004, no. 4.
4. Chestnykh, O.V., Lyzhin, V.A., and Koksharova, A.V., Hydrocarbon reserves in Russian forest floors, Lesovedenie, 2007, no. 6.
5. Efremova, T.T., Sekretenko, O.P., Avrova, A.F., et al., Geostatistical analysis of the spatial variation of the ash reserves in the litter of bog birch forests in western Siberia, Eurasian Soil Sci., 2013, vol. 46, no. 1, pp. 51–61.