GENCHEV, T. Opening address to the Session (in Bulgarian). Ann. Sofia Univ. Fac. Math. and Inf., [S. l.], v. 89, p. 9–10, 1997. Disponível em: https://ftl5.uni-sofia.bg./index.php/fmi/article/view/349. Acesso em: 24 nov. 2024.