TY  - BOOK
AU  - Cook, Thomas D.
AU  - Campbell, Donald T.
TI  - Quasi - Experimentation : design and analysis issues for field settings
SN  - 0395307902
AV  - QC6.4.C6 1979 
PB  - Houghton Mifflin
KW  - Physics - Experiments
KW  - Quasars
KW  - QC
N1  - Bibliography : p. 387-396; Includes index
ER  -