Increased risk of recurrent venous thromboembolism during hormone replacement therapy – results of the randomized, double-blind, placebo-controlled estrogen in venous thromboembolism trial (EVTET) - Høibraaten, E; Qvigstad, E; Arnesen, H; Larsen, S; Wickstrøm, E; Sandset, PM (Thromb Haemost, 2000)