Não informado. (1961). API Abstracts of Refining Patents. American Petroleum Institute.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रNão informado. API Abstracts of Refining Patents. New York: American Petroleum Institute, 1961.
एमएलए (8वां संस्करण) प्रशस्ति पत्रNão informado. API Abstracts of Refining Patents. American Petroleum Institute, 1961.
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