00720nam a22002657i 4500 20141212094101.0 981222s1998 sp gr 000 0 spa c 0963-8288 (papel) 1464-5165 (online) eng RIGBY, A.S. STATISTICAL METHODS IN EPIDEMIOLOGY. II: A COMMONSENSE APPROACH TO SAMPLE SIZE ESTIMATION Epidemiología Estadística Metodología Acción social Documental VAIL, A. DISABILITY AND REHABILITATION Vol. 20, no. 11 (1998), p. 405-410 65 G1a AR 19981222 R.1364 AR