Gonçalves, Daiane de Oliveira, Aline Costa Ramos, and Angela Leite Moreno. 2018. “Manipulative Material or Instrument: What Is Actually Being Used in Teaching Plane Analytical Geometry”. Sigmae 6 (2):54-61. https://publicacoes.unifal-mg.edu.br/revistas/index.php/sigmae/article/view/619.