1. Photography of the colon;Matsunga;Gastroent Endosc (Tokyo),1959
2. On photography of the colon and pharynx using gastro-camera;Niwa;Gastroent Endosc (Toyko),1960
3. Clinical experiences of colonic fiberscope;Niwa;Japan J Gastroenterol,1969
4. Clinical experience of colonic fiberscope;Niwa;Gastroent Endosc (Tokyo),1969
5. Flexible fiberoptic sigmoidoscopes;Overholt;CA,1969