@book{29522,
	author = {Levin, Jack. and Levin, William C.},
	title = {Fundamentos de estadística en la investigación social},
	publisher = {Harla ; Oxford,},
	year = {1977},
	address = {México :},
	edition = {2 ed.},
	note = {Trad. de : Elementary statistics in social research, 2 ed. de 1977}
}