Não informado. (1988). Nordic Journal of Freshwater Research. Institute of Freshwater Research.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रNão informado. Nordic Journal of Freshwater Research. Drottningholm, Suecia: Institute of Freshwater Research, 1988.
एमएलए (8वां संस्करण) प्रशस्ति पत्रNão informado. Nordic Journal of Freshwater Research. Institute of Freshwater Research, 1988.
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