Abstract

References
1.
Paulley
J W
. (1961 ) British Medical Journal
i , 462 .
2.
Powell
S J
. (1971 ) In: Management and Treatment of Tropical Diseases . Ed.
Maegraith
N G
Gilles
H M J
. Blackwell , Oxford ; p 3 .
3.
Stamm
W P
. (1970 )Lancet
ii , 1355 .
4.
Sepúlveda
B
Jurich
H
Bassols
F
Muñoz
R
. (1959 ) American Journal of Digestive Diseases
4 , 43 .
5.
Wright
R
. (1966 ) British Medical Journal
i , 957 .
