Oral care reduces pneumonia in older patients in nursing homes. - Yoneyama,T.; Yoshida,M.; Ohrui,T.; Mukaiyama,H.; Okamoto,H.; Hoshiba,K.; Ihara,S.; Yanagisawa,S.; Ariumi,S.; Morita,T.; Mizuno,Y.; Ohsawa,T.; et al. (JAGS, 2002)