1Campo R,Montserrat E,Brullet E.transnasal gastroscopy compared to conventional gastroscopy:a randomizedstudy of feasibility,safety and tolerance[].Endoscopy.1998
2Yagi J,Adachi K,Ari ma N,et al.A prospective randomized com-parative study on the safety and tolerability of transnasal esopha-gogastroduodenoscopy[].Endoscopy.2005
