Chandrasekhara Vinay, Zhang Lanjing, Floyd Beth N I, Kochman Michael L
Gastroenterology Division, Department of Internal Medicine, University of Pennsylvania Health System, Philadelphia, Philadelphia, USA.
Gastrointest Endosc. 2012 May;75(5):1111-2. doi: 10.1016/j.gie.2011.05.047. Epub 2011 Aug 5.