TY  - BOOK
AU  - Gerring John
TI  - Social science methodology :  A critical framework.   
SN  - 0 521 80113 3
U1  - Eb4, P1 
PY  - 2001///
CY  - New York
PB  - Cambridge university press USA      
KW  - Social Science
N1  - Bib p 259-92
ER  -