@book{7619,
	author = {Vázquez Cruz, Ruperto},
	title = {Estadística elemental},
	publisher = {Editorial Universitaria, Universidad de Puerto Rico},
	year = {1974, t.p. 1978, c1969.},
	address = {[Río Piedras]},
	edition = {6. ed.},
	note = {Includes index.}
}