Não informado. (1968). Professional Engineer. National Society of Professional Engineers.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रNão informado. Professional Engineer. Jersey City, NJ: National Society of Professional Engineers, 1968.
एमएलए (8वां संस्करण) प्रशस्ति पत्रNão informado. Professional Engineer. National Society of Professional Engineers, 1968.
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