Three months versus one year of oral anticoagulant therapy for idiopathic deep venous thrombosis - Agnelli, G; Prandoni, P; Santamaria, MG; Bagatella, P; Iorio, A; Bazzan, M; Moia, M; Guazzaloca, G; Bertoldi, A; Tomasi, C; Scannapieco, G; Ageno, W (N Engl J Med, 2001)