RT Journal Article SR Electronic T1 Efficacy of pneumococcal polysaccharide vaccine JF Canadian Medical Association Journal JO CMAJ FD Canadian Medical Association SP 1135 OP 1135 DO 10.1503/cmaj.1090019 VO 180 IS 11 A1 Ross M. Andrews A1 Sarah A. Moberley YR 2009 UL http://www.cmaj.ca/content/180/11/1135.1.abstract