TY  - BOOK
AU  - Devellis Robert F
TI  - Scale development :  Theory and applications   
T2  - Applied Social Research Methods Series, 26
SN  - 080393775X
U1  - SigmaObB, N1 
PY  - 1991///
CY  - London
PB  - Sage U K        
KW  - Social Sciences
ER  -