REFERENCES
- Aukee, S. Scand. J. Gastroent. 1972, 7, 567–574
- Gear, M. W. L., Truelove, S. C. & Whitehead, R. Gut 1971, 12, 639–645
- Imai, T., Kubo, T. & Watanabe, H. J. Nat. Cancer Inst. 1971, 47, 179–195
- Morson, B. C. J. Amer. Med. Ass. 1962, 179, 311–314
- Möllmann, K.-M., Bonnevie, O., Gudmand-Höyer, E. & Wulff, H. R. Scand. J. Gastroent. 1975, 10, 805–809
- Oddsson, E., Binder, V., Thorgeirsson, T., Jonasson, T. A., Gunnlaugsson, O., Wulff, M., Jonasson, K., Wulff, H. R., Bjarnason, O. & Riis, P. Scand. J. Gastroent. 1977, 12, 689–694
- Siurala, M., Isokoski, M., Varis, K. & Kekki, M. Scand. J. Gastroent. 1968, 3, 211–223
- Strickland, R. G. & MacKay, I. R. J. Digest. Dis. 1973, 18, 426–439