Babatunde Olowokure, Jeremy Hawker, Iain Blair, Nick Spencer
Olowokure B, Hawker J, Blair I, Spencer N.
Decrease in effectiveness of routine surveillance of Haemophilus influenzae disease after introduction of conjugate vaccine: comparison of routine reporting with active surveillance system
BMJ 2000; 321 :731
doi:10.1136/bmj.321.7263.731