Portwood, G., Maniatis, A., Jowell, P. S., Branch, M. S., Affronti, J., Guarisco, S., … Baillie, J. (1995). Diagnostic and therapeutic ERCP in the very old: Safe with a high success rate. Gastrointestinal Endoscopy, 41(4), 411–411. https://doi.org/10.1016/s0016-5107(05)80497-3

Portwood, G., A. Maniatis, P. S. Jowell, M. S. Branch, J. Affronti, S. Guarisco, P. B. Cotton, J. Leung, and J. Baillie. “Diagnostic and therapeutic ERCP in the very old: Safe with a high success rate.” Gastrointestinal Endoscopy 41, no. 4 (April 1995): 411–411. https://doi.org/10.1016/s0016-5107(05)80497-3.

Portwood G, Maniatis A, Jowell PS, Branch MS, Affronti J, Guarisco S, et al. Diagnostic and therapeutic ERCP in the very old: Safe with a high success rate. Gastrointestinal Endoscopy. 1995 Apr;41(4):411–411.

Portwood, G., et al. “Diagnostic and therapeutic ERCP in the very old: Safe with a high success rate.” Gastrointestinal Endoscopy, vol. 41, no. 4, Elsevier BV, Apr. 1995, pp. 411–411. Crossref, doi:10.1016/s0016-5107(05)80497-3.

Portwood G, Maniatis A, Jowell PS, Branch MS, Affronti J, Guarisco S, Cotton PB, Leung J, Baillie J. Diagnostic and therapeutic ERCP in the very old: Safe with a high success rate. Gastrointestinal Endoscopy. Elsevier BV; 1995 Apr;41(4):411–411.