Abstract

References
1.
Gandevia
B
. (1963 ) Brit. J. industr. Med.
20 , 204 .
2.
Kory
R C
Callahan
R
Boren
H G
Syner
J C
. (1961 ) Amer. J. Med.
30 , 243 .
3.
Lowe
C R
Pelmear
P L
Campbell
H
Hitchens
R A N
Khosla
T
King
T C
. (1968 ) Brit. J. prev. soc. Med.
22 , 1 .
4.
Peters
J M
Murphy
R L H
Pagnotto
L D
Van Ganse
W F
. (1968 ) Arch. environm. Hlth
16 , 642 .
5.
Williamson
K S
. (1965 ) Trans. Ass. industr. med. Offrs
15 , 29 .
