References
- Bibergall , J. A. 1966 . “Learning by Discovery: its relation to Science Teaching,” . Educational Review, University of Birmingham , 4 : 222 – 231 .
- Yager , R. E. , Engen , H. B. and Snider , B. C. F. 1969 . “Effects of the Laboratory and Demonstration Methods upon the Outcome of Instruction in Secondary Biology,” . Journal of Research in Science Teaching , 4 : 76 – 86 .