A case-control study of elderly patients with acute respiratory illness: effect of influenza vaccination on admission to hospital in winter 2003-2004. (Vaccine, 2007)

(untitled) - Jordan, R; Hawker, J; Ayres, J; Tunnicliffe, W; Adab, P; Olowokure, B; Kai, J; McManus, R; Salter, R; Cheng, K