Oral contraceptives and venous thromboembolism.

@article{Lidegaard1997OralCA,
  title={Oral contraceptives and venous thromboembolism.},
  author={Oejvind Lidegaard and Ian Milsom},
  journal={Lancet},
  year={1997},
  volume={349 9065},
  pages={1621; author reply 1622-3}
}