Do we adequately diagnose early gastric cancer in Turkey - KOÇ, Hüsnü Oğuz; SARI, Yavuz Selim; BEKTAŞ, Hasan; TUNALI, Vahit; ŞAHİN, Orhan; ÖZAKAY, Kerim; FEYZULLAH, Ersöz (Turkish Journal of Gastroenterology, 2011)