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2. APHA, AWWA, WPCF: 1985,Standard Methods for the Examination of Water and Wastewater, 16th edn., American Public Health Association, Washington D. C.
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4. Boon, P. J.: 1992, ?Essential Elements in the Case for River Conservation?, in: Boon, P. J., Calow, P. Petts, G. E., (Eds),River Conservation and Management John Wiley, Chichester, pp. 11?33.
5. Commission of the European Communities: 1975, Council Directive 75/440/EEC, On the Necessary Quality of Surface Waters for the Production of Drinking Water in the Member States?.