TY  - BOOK
AU  - Lehmann Irvin J Ed.
AU  -  Mehrens William A Ed.
TI  - Educational research: Readings in focus
SN  - 0-03-043016-X
PY  - 1971///
CY  - New York, USA
PB  - Holt, Rinehart and Winston 
KW  - Research Methods
ER  -