TY  - BOOK
AU  - MacMahon,Brian
AU  - Pugh,Thomas F.
TI  - Epidemiology: principles and methods 
SN  - 0031654263
PY  - 1970///
CY  - Boston
PB  - Little Brown & Co.
KW  - Epidemiology
N1  - Bibliography : p. 333-361
ER  -