CRAIG ALAN FEINSTEIN. The Collatz 3n+1 Conjecture is Unprovable. Global Journal of Science Frontier Research, [S. l.], v. 12, n. F8, p. 13–15, 2012. Disponível em: https://journalofscience.org/index.php/GJSFR/article/view/651. Acesso em: 8 may. 2024.