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Andjelkovic, T.; Perovic, J.; Purenović, M.; Blagojevic, S.; Nikolić, R.; Andjelkovic, D.; Bojic, A. A Direct Potentiometric Titration Study of the Dissociation of Humic Acid With Selectively Blocked Functional Groups. Eclet. Quim. 2006, 31, 39-46.