SHETH, I. H. On a Conjecture of Istratescu. The Journal of the Indian Mathematical Society, [S. l.], v. 38, n. 1-4, p. 337–338, 1974. Disponível em: https://informaticsjournals.com/index.php/jims/article/view/16708. Acesso em: 18 jul. 2024.