@article {67961,
	title = {Petroleum Systems of the United States},
	volume = {1870},
	year = {1988},
	pages = {1-68},
	institution = {Department of the Interior},
	keywords = {carbon, Coal, hydrocarbons, natural gas, Oil, petroleum, Sandstone, United States},
	isbn = {1870},
	author = {U.S. Geological Survey,},
	editor = {Magoon, Leslie B.}
}
