@book{239983,
	author = {Pagano, Robert R.},
	title = {Estadística para las ciencias del comportamiento},
	publisher = {Cengage Learning},
	year = {c2011.},
	address = {México},
	edition = {9th ed.},
	url = {http://www.loc.gov/catdir/enhancements/fy1212/2008937835-d.html}
}