TY  - BOOK
AU  - Otto, Hentry.J  .
AU  - Floyd,Hazel  .
AU  - Rouse,Margaret  .
TI  - Principles of elementary education / 
U1  - 372 
PY  - 1960///
CY  - Newyork : 
PB  - Rinehart and wimton , 
ER  -