@book{102290,
	author = {Campbell, Donald T, and Stanely, Julian C. and -.},
	title = {Experimental and quasi-experimental designs for research :},
	publisher = {Rand McNally & Co,},
	year = {1969.},
	series = {-},
	address = {Chiacago :},
	edition = {-.},
	note = {-.}
}