References
- Bianchi L, De Groote J, Desmet V J, Gedigk P, Korb G., Popper H, Poulsen H, Scheuer P J, Schmid M, Thaler H, Wepler W. Lancet 1977; 2: 914–919
- Hodges J R, Millward-Sadler G H, Wright R. Lancet 1982; 1: 550–552
- Bjarnason I, Magnusson B, Bjornsson S. Acta Med Scand 1982; 211: 305–307
- Population projections 1982–2025. Central Bureau of Statistics of Norway, Oslo 1982
- Koretz R L, Lewin K J, Higgins J, Fagen N D, Gitnick G L. Dig Dis Sci 1980; 25: 695–699
- Cook G C, Mulligan R, Sherlock S. Q J Med 1971; 40: 159–185
- Murray-Lyon I M, Stern R B, Williams R. Lancet 1973; 1: 735–737
- Soloway R D, Summerskill W HJ, Baggenstoss A H, Geall G, Gitnick G L, Elveback L R, Schoenfield M D. Gastroenterology 1972; 63: 820–833
- Opedal I, Ritland S, Elgjo K. Scand J Gastroenterol 1985; 20: 54–59, suppl 107