TY  - BOOK
AU  - Hart, K. M.
AU  - Brown, M. L.
AU  - Kuchemann, D. E.
TI  - Children's understanding of Mathematics: 11-16
SN  - 071953772X
AV  - DUCE QA14.39H 
PY  - 1981///
CY  - London
PB  - The CSMS Mathematical team
KW  - Science
N1  - Includes Appendix, Bibliographical index and references
ER  -