APA aipamena

Oppenheimer, E. J. (1980). Natural gas: The new energy leader. Pen and Podium Productions.

Chicago Style aipamena

Oppenheimer, Ernest J. Natural Gas: The New Energy Leader. New York, N.Y: Pen and Podium Productions, 1980.

MLA aipamena

Oppenheimer, Ernest J. Natural Gas: The New Energy Leader. Pen and Podium Productions, 1980.

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