Williams Muller, Elebe, et al. “Mastery and Conceptions of Student Fractions for Primary Education Teacher: A Comparative Study Between Spain and Nicaragua”. Revista Electrónica De Conocimientos, Saberes Y Prácticas, vol. 3, no. 1, June 2020, pp. 28-48, doi:10.5377/recsp.v3i1.9790.