Não informado. (1994). International Journal of Sustainable Development and World Ecology. Parthenon Publishing.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रNão informado. International Journal of Sustainable Development and World Ecology. Lancs, Inglaterra: Parthenon Publishing, 1994.
एमएलए (8वां संस्करण) प्रशस्ति पत्रNão informado. International Journal of Sustainable Development and World Ecology. Parthenon Publishing, 1994.
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