Bairral, Marcelo Almeida. “Prospective Mathematics Teachers Interacting in a Chat and Emerging Different Scopes about the Definition of Polyhedron”. Revista Internacional De Pesquisa En Educación Matemática, vol. 3, no. 2, July 2013, pp. 16-24, https://www.sbembrasil.org.br/periodicos/index.php/ripem/article/view/1140.