@misc{9634,
  author = {A. Walker},
  title = {Identification of esophageal cancer in the General Practice Research Database},
  year = {2011},
  journal = {Pharmacoepidemiol Drug Saf},
  volume = {20},
  number = {11},
  pages = {1159-67},
  issn = {1053-8569},
  doi = {10.1002/pds.2249},
}