Prospective comparison of endoscopic ultrasound-guided fine-needle aspiration and surgical histology in upper gastrointestinal submucosal tumors - Philipper, M.; Hollerbach, S.; Gabbert, H. E.; Heikaus, S.; Böcking, A.; Pomjanski, N.; Neuhaus, H.; Frieling, T.; Schumacher, B. (Endoscopy, 2010)