1. Alekhin, V.V., Complexes and construction of ecological association series, Byul. MOIP, 1924, vol. 32, nos. 1–2, pp. 99–111.
2. Barczi, A., Data for the botanical and pedological surveys of the Hungarian kurgans (Great Hungarian Plain, Hortobagy), Thaiszia J. Bot., 2003, vol. 13, pp. 113–126.
3. Beare, M.H., Coleman, D.C., Crossley, D.A., Jr., Hendrix, P.F., and Odum, E.P., A hierarchical approach to evaluating the significance of soil biodiversity to biogeochemical cycling, The Significance and Regulation of Soil Biodiversity, Ser. Dev. Plant Soil Sci., 1995, vol. 63, pp. 5–22.
4. Bityutskii, N.P., Mikroelementy vysshikh rastenii (Trace Elements of Higher Plants), St. Petersburg: Izd. SPbGU, 2011.
5. Blasius, J.H., Reise im europaisehen Russland in den Jahren 1840 und 1841. Ister Theil. Reise im Norden. Braunsehw, 1844.