1. Units of quantity: a conceptual basis common to additive and multiplicative structures;Behr,1994
2. The mental representation of numerical fractions: real or integer?;Bonato;Journal of Experimental Psychology: Human Perception and Performance,2007
3. Theory of didactical situations in mathematics;Brousseau,2002
4. What kinds of numbers do students assign to literal symbols? Aspects of the transition from arithmetic to algebra;Christou;Mathematical Thinking and Learning,2012
5. Equipartitioning/splitting as a foundation of rational number reasoning using learning trajectories;Confrey,2009