@misc{9817,
  author = {S. Jick and K. Hagberg and J. Kaye and H. Jick},
  title = {The risk of unintended pregnancies in users of the contraceptive patch compared to users of oral contraceptives in the UK General Practice Research Database},
  year = {2009},
  journal = {Contraception},
  volume = {80},
  number = {2},
  pages = {142-51},
  issn = {0010-7824},
  doi = {10.1016/j.contraception.2009.02.013},
}