@book{30504,
	author = {Averitt, Paul,},
	title = {Coal resources of the United States, January 1, 1967.},
	publisher = {U.S. Govt. Print. Off.,},
	year = {1969.},
	series = {Geological Survey bulletin 1275},
	address = {Washington,},
	note = {"Supersedes Bulletin 1136."}
}