1. Endoscopic comparison of the duodenal bulb: a comparison with x-ray;Belber, J.P.;Gastroenterology,1971
2. An evaluation of the gastroduodenal fibrescope;Burnett, W.;Gut,1962
3. Fibreendoscopy of the intestines;Classen, M.;Gut,1971
4. Duodenitis: frequency and significance;Classen, M.; Koch, H.; Demling, L.;Bibl. gastroent. (Basel),1970
5. Cannulation of papilla of Vater via fiber-duodenoscope;Cotton, P.B.; Salmon, P.R.; Blumgart, L.H.; Burwood, R.J.; Davies, G.T.; Lawrie, B.W.; Pierce, J.W.; Read, A.E.;Lancet,1972