FORT, M. K. Open Topological Disks in the Plane. The Journal of the Indian Mathematical Society, [S. l.], v. 18, n. 1, p. 23–26, 1954. DOI: 10.18311/jims/1954/17015. Disponível em: http://www.informaticsjournals.com/index.php/jims/article/view/17015. Acesso em: 17 may. 2024.