@book{627,
	author = {Babbie, Earl R.},
	title = {The practice of social research /},
	publisher = {Thomson Wadsworth,},
	year = {c2007.},
	address = {Belmont, CA :},
	edition = {11th ed.},
	url = {http://www.loc.gov/catdir/enhancements/fy1515/2005932100-b.html}
}