Leffler, W. L., & Womack, K. (2014). Natural gas liquids: A nontechnical guide. PennWell Corporation.
Chicago Style (17. basım) AtıfLeffler, William L., ve Karla Womack. Natural Gas Liquids: A Nontechnical Guide. Tulsa, Oklahoma: PennWell Corporation, 2014.
MLA (9th ed.) AtıfLeffler, William L., ve Karla Womack. Natural Gas Liquids: A Nontechnical Guide. PennWell Corporation, 2014.
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