Não informado. (1974). Key-word-index of Wildlife Research. Swiss Wildlife Information Service.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रNão informado. Key-word-index of Wildlife Research. Zurich, Suíça: Swiss Wildlife Information Service, 1974.
एमएलए (8वां संस्करण) प्रशस्ति पत्रNão informado. Key-word-index of Wildlife Research. Swiss Wildlife Information Service, 1974.
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