Author,Title,Journal,ISSN,Publisher,Date,Volume,Number,Page,URL,URL(DOI) GUDA NM,Inter-and intra-observer variability in the measurement of length at endoscopy : implications for the measurement of Barrett's esophagus,Gastrointest Endosc,,,2004,59,,655-658,https://cir.nii.ac.jp/crid/1570572700608268288,