Abstract

References
1.
Johnson
H D
(1948 ) Postgrad med. J.
24 , 193
2.
Johnson
H D
(1955 ) Lancet
i , 266
3.
Orr
I M
Johnson
H D
(1947 ) Lancet
ii , 84
4.
Quigley
J P
(1942 ) Arch. Surg., Chicago
44 , 414
