@book{36896,
	author = {Friis, Robert H. and Sellers, Thomas A.},
	title = {Epidemiology for public health practice /},
	publisher = {Jones and Bartlett Publishers,},
	year = {c2009.},
	address = {Sudbury, Mass. :},
	edition = {4th ed.},
	url = {http://www.loc.gov/catdir/toc/ecip087/2007051846.html}
}