@book{210393,
	author = {Leech, Nancy L. and Barrett, Karen Caplovitz.},
	title = {SPSS for intermediate statistics},
	publisher = {L. Erlbaum Associates},
	year = {c2008.},
	address = {New York},
	edition = {3rd ed.},
	note = {ESTE LIBRO INCLUYE UN DISCO},
	url = {http://www.loc.gov/catdir/toc/ecip0715/2007013984.html}
}