Valdemoros, Marta Elena, and Elena Fabiola Ruiz. “THE CASE OF LUCINA FOR THE STUDY OF FRACIONS IN ADULT SCHOOL”. Revista Latinoamericana de Investigación en Matemática Educativa, vol. 11, no. 1, Jan. 2008, pp. 93-125, https://www.relime.org/index.php/relime/article/view/361.