IVANOV, L. SKORDEV’S CONTRIBUTION TO RECURSION THEORY. Ann. Sofia Univ. Fac. Math. and Inf., [S. l.], v. 90, p. 9–15, 1998. Disponível em: https://admin.uni-sofia.bg/index.php/fmi/article/view/283. Acesso em: 23 jan. 2025.