@book{36988,
	author = {Lee, I-Min.},
	title = {Epidemiologic methods in physical activity studies},
	publisher = {Oxford University Press,},
	year = {2009.},
	address = {New York ;},
	url = {http://dx.doi.org/10.1093/acprof:oso/9780195183009.001.0001}
}