1. ADAIR, F. E, (1930), Ann. Surg., 91, I97.
2. ADAIR, F. E. (1949), Ann. R. Coll. Surg. Engl., 4, 360.
3. BLOODGOOD, J. C. (1922), J. Amer. med. Ass., 78, 859.
4. CAMPBELL, O. J. (1946), Surgery, 19, 40.
5. SETES, A. C., and C, PHILLIPS (1949), Surg, Gynec, Obstet,, 89, 345, GRAY, H. K., and G. A. WOOD (1941), Arch. Surg., 42, 203.