Abstract

References
1.
Barker
E M
. (1958 ) S. Afr. med. J.
32 , 634 .
2.
Duncan
H J
. (1964 ) S. Afr. med. J.
38 , 413 .
3.
Gonzalez
C B
Astacio
J N
. (1964 ) Dis. Colon Rect.
7 , 548 .
4.
Juniper
K
. (1962 ) Amer. J. Med.
33 , 377 .
