TY  - BOOK
AU  - Thier,Herbert D.
TI  - Teaching elementary school science : : a laboratory approach 
U1  - 372.35 
PY  - 1973///.
CY  - New Delhi : 
PB  - Sterling Publishers Private Limited, 
KW  - Science--Study and teaching (Elementary)
N1  - Includes index.
ER  -