Hannaford, Philip C2012-05-292012-05-292011-10-25Hannaford, P C 2011, 'The progestogen content of combined oral contraceptives and venous thromboembolic risk', British Medical Journal, vol. 343, d6592. https://doi.org/10.1136/bmj.d65920959-8146http://hdl.handle.net/2164/24452143595engRoyal-CollegeuserspillR MedicineRThe progestogen content of combined oral contraceptives and venous thromboembolic riskJournal item10.1136/bmj.d6592343