TY  - BOOK
AU  - COOK Thomas D
AU  - Donald T. Campbell
TI  - Quasi- Experimentation: Design and Anaysis Issues for Field Settings
SN  - 0395307902
U1  - 001.4  
PY  - 1979///
CY  - Boston
PB  - Houghton Mifflin Company
N1  - Includes bibliographical references and index
ER  -