TY  - BOOK
AU  - Hellevik Ottar
TI  - Introduction to causal analysis :  Exploring survey   
T2  - Contemporaty social research series, 9
SN  - 0043120202
U1  - Sigma b4, M4 
PY  - 1984///
CY  - London
PB  - Allen and Unwin UK       
KW  - Social Science
N1  - Bib p 205-08
ER  -