Effect of Clopidogrel Added to Aspirin in Patients with Atrial Fibrillation
NEJM 360:2066-2078,2127, The ACTIVE Investigators, 2009
Use of Single and Combined Antithrombotic Therapy and Risk of Serious Upper Gastrointestinal Bleeding: Population Based Case-Control Study
BMJ 333:726-728, Hallas,J.,et al, 2006