@book{67448,
	author = {Levenhagen, John I. and Spethmann, Donald H.},
	title = {HVAC controls and systems /},
	publisher = {McGraw-Hill,},
	year = {c1993.},
	address = {New York :},
	note = {Includes index.},
	url = {http://www.loc.gov/catdir/bios/mh041/92025594.html}
}