TY  - BOOK
AU  - Belson William A
TI  - Validity in survey research:  with special reference   
SN  - 0566005107
U1  - X:511.3.N8, M6 
PY  - 1986///
CY  - Hants
PB  - Survey Research         
KW  - Marketing
N1  - Bibliography: P544-552
ER  -