00503nas a2200181   4500000000100000000000100001008004100002100001600043700001500059700001200074700001400086700001600100700001200116245016000128300001100288490000800299022001400307       2009                            d1 aP. Thompson1 aR. Gilbert1 aP. Long1 aS. Saxena1 aM. Sharland1 aI. Wong00aEffect of antibiotics for otitis media on mastoiditis in children: a retrospective cohort study using the United kingdom general practice research database  a424-300 v123  a0031-4005