European Journal of Epidemiology
European Journal of Epidemiology > 1997 > 13 > 5 > 573-580
European Journal of Epidemiology > 1997 > 13 > 8 > 959-962
European Journal of Epidemiology > 1997 > 13 > 5 > 573-580
European Journal of Epidemiology > 1997 > 13 > 8 > 959-962