Morales Parra, Samuel, and Carmen Samper. “Difficulties in Learning the Formal Deductive Demonstration in Euclidean Geometry”. Amazonia Investiga 4, no. 6 (June 28, 2015): 55-68. Accessed May 17, 2024. https://www.amazoniainvestiga.info/index.php/amazonia/article/view/685.