Dyfyniad APA

Leffler, W. L., & Womack, K. (2014). Natural gas liquids: A nontechnical guide. PennWell Corporation.

Dyfyniad Arddull Chicago

Leffler, William L., and Karla Womack. Natural Gas Liquids: A Nontechnical Guide. Tulsa, Oklahoma: PennWell Corporation, 2014.

Dyfyniad MLA

Leffler, William L., and Karla Womack. Natural Gas Liquids: A Nontechnical Guide. PennWell Corporation, 2014.

Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.