1Ollendorf DA,Veral lonch M. Oster G Gost of venous thromboembolisn following major orthopedic surgery in hospitalized patients. Am J Health Syst Pham, 2002, 59 ( 18 ) : 1750 - 1754.
2Lensing AW, Buller HR, Prandoni P, et al. Contrast Venography,the gold standard for the diagnosis deep vein thrombosis: improvement in observer agreement [ J ]. Thromb Haemost, 1992,67:8 - 12.
