RT Journal Article SR Electronic T1 Pertussis: a significant cause of prolonged acute cough in previously vaccinated school-aged children JF Evidence Based Medicine JO Evid Based Med FD BMJ Publishing Group Ltd SP 35 OP 35 DO 10.1136/ebmed-2014-110072 VO 20 IS 1 A1 Michael D Shields YR 2015 UL http://ebm.bmj.com/content/20/1/35.abstract AB