A. AYDIN, F. TEKİN, F. GÜNŞAR, A. GÜLER, M. TUNÇYÜREK, and T. İLTER, “Value of endoscopic ultrasonography for upper gastrointestinal stromal tumors: A single center experience”, Turkish Journal of Gastroenterology, vol. 15, no. 4, pp. 233–237, Jan. 2004.