Abstract

References
1.
Cook
J
Altaian
D G
Moore
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Topp
S G
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W W
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(1973 ) British Journal of Preventive and Social Medicine
27 , 91
2.Department of Health Social Security (1969 ) Reports on Public Health and Medical Subjects No. 120
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Topp
S G
Cook
J
Elliott
A
(1972 ) British Journal of Preventive and Social Medicine
26 , 106
