TY  - BOOK
ED  - The National Council of Teachers of M.; Twenty-first yearbook
TI  - The Learning of mathematics:its theory and practice
U1  - 510.5 N272l 
PY  - 1967///
CY  - Washington
PB  -  NCTM
KW  -  Matemáticas
KW  - Enseñanza
KW  - Estados Unidos
KW  - Anuarios
ER  -