1. Aivazyan, S.A., Buchstaber, V.M., Enyukov, I.S., and Meshalkin, L.D., Prikladnaya statistika: klassifikatsiya i snizhenie razmernosti (Applied Statistics: Classification and Dimension Reduction), Moscow: Finansy i statistika, 1989.
2. Dedu, I.I., Ekologicheskii entsiklopedicheskii slovar' (Ecological Encyclopedic Dictionary), Kishinev: Glavnaia redaktsiia Moldavskoi sovetskoi entsiklopedii, 1990.
3. Dolgonosov, B.M. and Korchagin, K.A., Seasonal variations of the distribution of river water quality, Water Resour., 2014, vol. 41, no. 1, pp. 46–54.
4. Fedorov, V.D., Sakharov, V.B., and Levich, A.P., Quantitative approaches to the problem of evaluation of norm and pathology of ecosystems, in Chelovek i biosfera (Man and the Biosphere), Moscow: Mosk. Univ., 1982, no. 6, pp. 3–42.
5. Gelashvili, D.B., Korolev, A.A., and Basurov, V.A., Zoning of the territory according to the degree of load of sewage with the help of generalized desirability function, Povolzh. Ekol. Zh., 2006, nos. 2/3, pp. 129–138.