Rocha, Maria Isabel, and Hugo Alexandre Menino. “DEVELOPMENT OF NUMBER SENSE IN MULTIPLICATION. A CASE STUDY WITH CHILDREN OF 7 8 YEARS OLD”. Revista Latinoamericana de Investigación en Matemática Educativa, vol. 12, no. 1, Jan. 2009, pp. 103-34, https://www.relime.org/index.php/relime/article/view/342.