Orgaran (Org 10172) or heparin for preventing venous thrombosis after elective surgery for malignant disease? - Gallus, A; Cade, J; Ockelford, P; Hepburn, S; Maas, M; Magnani, H; Buck, nall; Stevens, J; Port, eous (A double-blind, randomised, multicenter comparison, 1993)