@book{49844,
	author = {McKown, Harry C. and Roberts, Alvin},
	title = {Audio-visual aids to instruction /},
	publisher = {McGraw-Hill book company, inc,},
	year = {1949},
	series = {McGraw-Hill series in education, Harold Benjamin, consulting editor},
	address = {New York and :},
	edition = {2d ed. },
	note = {"Selected references" at end of each chapter except chapter III. "Sources of materials and equipment": p.579-595}
}