The risk of recurrent venous thromboembolism in carriers and non-carriers of the G1691A allele in coagulation factor V gene and the G20210A allele in the prothrombin gene - Lindmarker, P; Schulman, S; Sten-Linder, M; Wiman, B; Egberg, N; Johnsson, H; and the DURAC Trial Study Group (Thromb Haemost, 1999)