GENCHEV, T. Opening address to the Session (in Bulgarian). Ann. Sofia Univ. Fac. Math. and Inf., [S. l.], v. 91, p. 11–12, 1999. Disponível em: https://ftl5.uni-sofia.bg/index.php/fmi/article/view/264. Acesso em: 21 nov. 2024.