@book{37012,
	author = {Ullmann, John E.},
	title = {Teoría y problemas sobre métodos cuantitativos en administración.},
	publisher = {McGraw-Hill },
	year = {1980.},
	series = {Ser. de Compendios Schaum.},
	address = {México },
	note = {Tr. de: Quantitative methods in management.}
}