Busby, R. L., & Technology, I. o. G. (1999). Natural gas in nontechnical language. Tulsa, OK : Pennwell.
Lua i Stíl Chicago (17ú heag.)Busby, Rebecca L., agus Institute of Gas Technology. Natural Gas in Nontechnical Language. Tulsa, OK : Pennwell, 1999.
Lua MLA (9ú heag.)Busby, Rebecca L., agus Institute of Gas Technology. Natural Gas in Nontechnical Language. Tulsa, OK : Pennwell, 1999.
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