SOSKOVA, A.; SOSKOV, I. ADMISSIBILITY IN $\sum_n^0$-ENUMERATIONS. Ann. Sofia Univ. Fac. Math. and Inf., [S. l.], v. 90, p. 77–90, 1998. Disponível em: https://annual.uni-sofia.bg/index.php/fmi/article/view/287. Acesso em: 9 apr. 2025.