Não informado. (1999). International Mining & Minerals. Institution of Mining Engineers.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रNão informado. International Mining & Minerals. Doncaster, Inglaterra: Institution of Mining Engineers, 1999.
एमएलए (8वां संस्करण) प्रशस्ति पत्रNão informado. International Mining & Minerals. Institution of Mining Engineers, 1999.
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