Oral Contraception and Risk of a Cerebral Thromboembolis Attack:Results of a Case-Control Study
BMJ 306:956-963, Kidegaard,O., 1993
The Evolution of Oral Contraceptives Maximizing Efficacy, Minimizing Risks
Acta Obstet Gynecol Scand (Suppl) 152:7-12990., Hedon,B., 1990