Não informado. (1961). Petroleum Abstracts. University of Tulsa, Information Services Division.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रNão informado. Petroleum Abstracts. Tulsa, Okla: University of Tulsa, Information Services Division, 1961.
एमएलए (8वां संस्करण) प्रशस्ति पत्रNão informado. Petroleum Abstracts. University of Tulsa, Information Services Division, 1961.
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