TY - JOUR AU - Leaper, M TI - Reasons for failure to diagnose colorectal carcinoma at colonoscopy JO - Endoscopy VL - 36 PY - 2004 DO - 10.1055/s-2004-814399 L3 - PubMed-ID: 15202045 SP - 499 EP - 503 N1 - et al. ER -