REFERENCES
- Casten, D. F. Arch. Surg. 1964, 88, 255–259
- Crumplin, M. K. H., Stol, D. W., Murphy, G. M. & Collis, J. L. Brit. J. Surg. 1974, 61, 611–616
- Csendes, A., Larrain, A. & Uribe, P. Ann. Surg. 1974, 179, 119–122
- Giles, G. R., Clark, C. G. & Buchan, R. Gut 1968, 9, 52–56
- Gillison, E. W., de Castro, V. A. M., Nyhus, L. M., Kusakari, K. & Bombeck, C. T. Surg. Gynec. Obstet. 1972, 134, 419–424
- Goldberg, H. I., Dodds, W. J., Gee, S., Montgomery, C. & Zboralske, F. F. Gastroenterology 1969, 56, 223–230
- Gravgaard, E. Scand. J. Gastroent. 1968, 3, 327–333
- Heisingen, N. Acta Chir. Scand. 1960, 118, 190–201
- Henderson, R. D., Mugashe, F. L., Jeejeebhoy, K. N., Szczpanski, M. M., Cullen, J., Marryatt, G. & Boszko, A. Canad. J. Surg. 1973, 16, 12–16
- Jepson, K., Lari, J., Humphrey, C. S., Smith, R. B., Wilkinson, A. R. & Johnston, D. Ann. Surg. 1973, 178, 769–772
- Konturek, S. J., Wysocki, A. & Oleksy, J. Gastroenterology 1968, 54, 392–400
- Lippa, F. H. & Thal, A. P. Arch. Surg. 1966, 93, 148–153
- Nundy, S. & Baron, J. H. Amer. J. Dig. Dis. 1974, 19, 137–142
- Redo, S. F., Barnes, W. A. & de la Sierra, A. O. Ann. Surg. 1959, 149, 556–564
- Siegel, S. Nonparametric Statistics for the Behavioral Sciences (International student edition) McGraw-Hill, Kogakusha. Tokyo, 1956
- Silber, W. Gut 1969, 10, 614–616
- Skandalakis, J. E., Rowe, J. S., Gray, S. W. & Androulakis, J. A. Surgery 1974, 75, 233–237
- Sörensen, H. R. & Boesby, S. to be published
- Squire, B. H., Glick, S. & Benn, A. Thorax 1968, 23, 683–685
- Stanciu, C. Amer. J. Gastroent. 1975, 63, 104–107
- Stol, D. W., Murphy, G. M. & Collis, J. L. Scand. J. Gastroent. 1974, 9, 97–101
- Ward, A. S. Gut 1970, 11, 738–742
- Williams, C. B., Lawrie, J. H. & Forrest, A. P. M. Lancet 1967, 1, 184–185
- Winkelstein, A., Wolf, B. S., Som, M. L. & Marshak, R. H. J. Amer. Med. Ass. 1954, 154, 885–889