TY  - BOOK
AU  - Campbell,Donald T.
TI  - Experimental & quasi-experiment : designs for research / 
U1  - 300.72 
PY  - 1963///
CY  - Chicago
PB  - Rand Mc-Nally, 
KW  - Social sciences
KW  - Education
KW  - Science
KW  - Statistics
KW  - Social research
KW  - Studies
ER  -