GRACE, J. H. On Feuerbach’s Theorem. The Journal of the Indian Mathematical Society, [S. l.], v. 9, n. 3, p. 94–99, 1917. DOI: 10.18311/jims/1917/17604. Disponível em: https://informaticsjournals.com/index.php/jims/article/view/17604. Acesso em: 5 may. 2024.