@misc{9656,
  author = {P. Walters and P. Schofield and L. Howard and M. Ashworth and A. Tylee},
  title = {The relationship between asthma and depression in primary care patients: a historical cohort and nested case control study},
  year = {2011},
  journal = {PLoS One},
  volume = {6},
  number = {6},
  pages = {e20750},
  issn = {1932-6203},
  doi = {10.1371/journal.pone.0020750},
}