Não informado. (1989). Water Environment & Technology. Water Pollution Control Federation.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रNão informado. Water Environment & Technology. Alexandria, Va: Water Pollution Control Federation, 1989.
एमएलए (8वां संस्करण) प्रशस्ति पत्रNão informado. Water Environment & Technology. Water Pollution Control Federation, 1989.
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