Gasco- Txabarri, Javier. “Arithmetic - Algebraic Problem Solving and Learning Strategies in Maths. An Study in Secondary Education”. Revista Latinoamericana de Investigación en Matemática Educativa, vol. 20, no. 2, July 2017, pp. 167-92, https://doi.org/10.12802/relime.17.2022.