@article{vergison_hanquet_2012, 
  title={Challenges in Estimating the Impact of Pneumococcal Conjugate Vaccines Through Surveillance}, 
  volume={31}, 
  DOI={10.1097/inf.0b013e31824bc1f0}, 
  publisher={Ovid Technologies (Wolters Kluwer Health)}, 
  author={Vergison and Hanquet}, 
  year={2012}
  }