References
- 1972 . Science: Understanding Your Environment , Morristown , N.J. : Silver Burdett Co. .
- Kauchek , Donald and Eggen , Paul . 1980 . Exploring Science in the Elementary Schools , Chicago : Rand McNally .
- Nelson , Leslie W. and Lorbeer , George C. 1979 . Science Activities for Elementary Children , Dubuque , Iowa : Wm. C. Brown Pub. .