@book{9448,
	author = {Snedecor, George W. and Cochran, William Gemmell, },
	title = {Statistical methods /},
	publisher = {The Iowa State University, },
	year = {c1967},
	address = {Ames, IO :},
	edition = {6 ed.},
	url = {https://www.cicy.mx/sitios/sib/doctoelectronico/10192.pdf}
}