A randomized controlled trial of low-molecular-weight heparin (Enoxaparin) to prevent deep-vein thrombosis in patients undergoing elective hip surgery - Turpie, AGG; Levin, MN; Hirsh, J; Carter, CJ; Jay, RM; Powers, PJ; Andrew, M; Hull, RD; Gent, M (N Engl J Med, 1987)