@book{294815,
	author = {Russell, R.i.},
	title = {Pruebas y técnicas de investigación : vol.6 no 2 / director R.I.Russell.},
	publisher = {Salvat Editores S.a},
	year = {1979},
	series = {Clínica Gastroenterológica},
	address = {Barcelona}
}