TY  - BOOK
AU  - Martorella Peter H
TI  - Concept learning in the social studies models for
SN  - 070022280
U1  - T:2(Siam), L1 
PY  - 1971///
CY  - Toronto
PB  - Internaitonal Textbook Co        
KW  - Education
N1  - Bib at the end of each chapter
ER  -