DEMIRCIOĞLU, H. Preservice mathematics teachers’ proving skills in an incorrect statement: Sums of triangular numbers. Pegem Journal of Education and Instruction, [S. l.], v. 13, n. 1, p. 326–333, 2022. DOI: 10.47750/pegegog.13.01.36. Disponível em: https://pegegog.net/index.php/pegegog/article/view/2335. Acesso em: 6 aug. 2025.