Não informado. (1987). International Journal of Surface Mining, Reclamation and Environment. Balkema.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रNão informado. International Journal of Surface Mining, Reclamation and Environment. Rotterdam, Holanda: Balkema, 1987.
एमएलए (8वां संस्करण) प्रशस्ति पत्रNão informado. International Journal of Surface Mining, Reclamation and Environment. Balkema, 1987.
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