1. ARMITAGE, G., and WILSON, M. (1950), Brit. J. Surg., 38, 182.
2. 'The Moder Management;BARGEN, J.; A.,1943
3. BARGEN, J. A., and WEBER, H. M. (1930), Surg. Gyn. Obst., 50, 964.
4. BUTLER, E. C. B. (1953), Proc. Roy. Soc. Med., 46, 69.
5. CORBETT, R. S. (1945), Ibid., 38, 277.