Não informado. (1970). Pipeline and Gas Journal. Petroleum Engineer Publishing.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रNão informado. Pipeline and Gas Journal. Dallas, Tex: Petroleum Engineer Publishing, 1970.
एमएलए (8वां संस्करण) प्रशस्ति पत्रNão informado. Pipeline and Gas Journal. Petroleum Engineer Publishing, 1970.
चेतावनी: ये उद्धरण हमेशा 100% सटीक नहीं हो सकते हैं.