@book{2658,
	author = {Sechrest, Lee. and National Center for Health Services Research and Health Care Technology Assessment (U.S.)},
	title = {Research methodology :},
	publisher = {U.S. Dept. of Health and Human Services, Public Health Service, Agency for Health Care Policy and Research ;},
	year = {[1990]},
	address = {Rockville, MD :},
	note = {Proceedings of the conference "Research Methodology: Strengthening Causal Interpretations of Nonexperimental Data," held in Tucson, Arizona, April 8-10, 1987 and sponsored by the National Center for Health Services Research and Health care Assessment, now the Agency for Health Care Policy and Research, with the support of the Dept. of Psychology, University of Arizona.}
}