DITCHEV, A. Characterization of the structures which admit effective enumerations. Ann. Sofia Univ. Fac. Math. and Inf., [S. l.], v. 92, p. 7–16, 2000. Disponível em: https://stipendii.uni-sofia.bg/index.php/fmi/article/view/251. Acesso em: 23 nov. 2024.