@book{293842,
	author = {United States.},
	title = {Future of federal coal :},
	publisher = {U.S. Government Printing Office,},
	year = {2006.},
	address = {Washington :},
	note = {"Serial no. 109-51."},
	url = {http://purl.access.gpo.gov/GPO/LPS73896}
}