1. Representations, strategies, cognitive load, and effective learning and teaching of linear equation solution procedures;Atweh,1994
2. Activity math: Using manipulatives in the classroom;Bloomer,1993
3. Equations revisited;Booth,1987
4. Children's difficulties in beginning algebra;Booth,1988
5. The values and limitations of using concrete representations to teach mathematics to young children;Boulton-Lewis,1991