@misc{9021,
  author = {K. Rothnie and H. Mullerova and J. Hurst and L. Smeeth and K. Davis and S. Thomas and J. Quint},
  title = {Validation of the Recording of Acute Exacerbations of COPD in UK Primary Care Electronic Healthcare Records},
  year = {2016},
  journal = {PLoS One},
  volume = {11},
  number = {3},
  pages = {e0151357},
  issn = {1932-6203},
  doi = {10.1371/journal.pone.0151357},
}