Não informado. (1971). Petroleum Refining and Petrochemicals Literature Abstracts. American Petroleum Institute.
Παραπομπή σε μορφή Chicago (17η εκδ.)Não informado. Petroleum Refining and Petrochemicals Literature Abstracts. New York: American Petroleum Institute, 1971.
Παραπομπή σε μορφή MLA (8th εκδ.)Não informado. Petroleum Refining and Petrochemicals Literature Abstracts. American Petroleum Institute, 1971.
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