Influence of variability of interpretation of contrast venography for screening of postoperative deep venous thrombosis on the results of a thromboprophylactic study - Couson, F; Bounameaux, C; Didier, D; Geiser, D; Meyerovitz, M F; Schmitt, H E; Schneider, P A; Bounameaux, H (Thromb Haemost, 1993)