Mayén, Silvia, Carmen Batanero, and Carmen Díaz. 2009. “SEMIOTIC CONFLICTS OF MEXICAN STUDENTS FOR A PROBLEM OF COMPARISON OF ORDINAL DATA”. Revista Latinoamericana de Investigación en Matemática Educativa 12 (2): 151-78. https://www.relime.org/index.php/relime/article/view/334.