@book{26156,
	author = {Butler, G. M. and Allen, Milton Arthur,},
	title = {Petroleum,},
	publisher = {University of Arizona, Bureau of Mines,},
	year = {1921.},
	series = {Arizona. State Bureau of Mines. Bulletin,},
	address = {Tucson, Ariz.,},
	note = {At head of title: ... University of Arizona bulletin.}
}