Arnau, David, and Luis Puig. “Performances of Students Trained in Algebraic Problem Solving in a Spreadsheet Environment and Their Relation to Their Competence in the Cartesian Method”. Enseñanza De Las Ciencias. Revista De investigación Y Experiencias didácticas, vol. 31, no. 3, Nov. 2013, pp. 49-66, doi:10.5565/rev/ec/v31n3.967.