B.J. Reid, R.C. Haggitt, C.E. Rubin, G. Roth, C.M. Surawicz, G. Van Belle, K. Lewin, W.M. Weinstein, D.A. Antonioli, H. Goldman, W. MacDonald, D. Owen,
Observer variation in the diagnosis of dysplasia in Barrett's esophagus Human Pathology. ,vol. 19, pp. 166- 178 ,(1988) ,
10.1016/S0046-8177(88)80344-7