1. The development of mental arithmetic: A chronometric approach;Ashcraft;Developmental Review,1982
2. The development of children's number ideas in the primary grades;Brownell,1928
3. The child's understanding of number;Gelman,1978
4. The development of children's mathematical thinking: Connecting research and practice;Ginsburg,1998
5. A chronometric analysis of simple addition;Groen;Psychological Review,1972