SARIEV, A.; GANCHEV, H. Definability issues in the ω-Turing degrees. Ann. Sofia Univ. Fac. Math. and Inf., [S. l.], v. 105, p. 45–54, 2018. DOI: 10.60063/gsu.fmi.105.45-54. Disponível em: https://ftl5.uni-sofia.bg./index.php/fmi/article/view/11. Acesso em: 24 nov. 2024.