Não informado. (2009). International Gas Engineering and Management. Institution of Gas Engineers.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रNão informado. International Gas Engineering and Management. London: Institution of Gas Engineers, 2009.
एमएलए (8वां संस्करण) प्रशस्ति पत्रNão informado. International Gas Engineering and Management. Institution of Gas Engineers, 2009.
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