References
- Kaput , J.J. , Carraher , D. and Blanton , M.L. 2007 . Algebra in the early grades , Mahwah , NJ : Lawrence Erlbaum .
- Kieran , C. 2006 . “ Research on the learning and teaching of algebra ” . In Handbook of research on the psychology of mathematics education: Past, present and future , Edited by: Gutierrez , A. and Boero , P. 11 – 49 . Rotterdam : Sense .