STANDARD. (1998). Standard methods for the examination of water and wastewater.-- ed.20. APHA.
Chicago Style aipamenaSTANDARD. Standard Methods for the Examination of Water and Wastewater.-- Ed.20. Maryland: APHA, 1998.
MLA aipamenaSTANDARD. Standard Methods for the Examination of Water and Wastewater.-- Ed.20. APHA, 1998.
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