TY  - BOOK
AU  - Husen Torsten Ed.
TI  - International study of achievement in mathematics
U1  - T:3,(B).1.N6, K7.2 
PY  - 1967///
CY  - New York
PB  - John Wiley        
KW  -  Education
KW  - Teaching Techniques
N1  - International project for the evaluation of educational achievement
ER  -