1. Arinushkina, E.V., Rukovodstvo po khimicheskomu analizu pochv (Guide on Soil Chemical Analyses), Moscow: Mosk. Gos. Univ., 1970.
2. Linnik, P.N. and Nabivanets, B.I., Formy migratsii metallov v presnykh poverkhnostnykh vodakh (Metal Migration Forms in Fresh Surface Waters), Leningrad: Gidrometeoizdat, 1986.
3. Adani, F., Ricca, G., Tambone, F., and Genevini, P., Isolation of the stable fraction, the core of the humic acid, Chemosphere, 2006, vol. 65, no. 8, pp. 1300–1307.
4. Aiken, G.R., Isolation and concentration techniques for aquatic humic substances, Humic Substances in Soil, Sediment and Water: Geochemistry and Isolation, Aiken G.R., McKnight, D.M., Wershaw, R.L., and MacCarthy, P., Eds., N. Y.: Wiley, 1985, pp. 363−385.
5. Albinet, A., Minero, C., and Vione, D., Photochemical generation of reactive species upon irradiation of rainwater: negligible photoactivity of dissolved organic matter, Sci. Total Environ., 2010, vol. 408, no. 16, pp. 3367–3373.