On a class of meromorphic functions with negative coefficients. Annual of Sofia University St. Kliment Ohridski. Faculty of Mathematics and Informatics, [S. l.], v. 93, p. 55–60, 2001. Disponível em: https://annual.uni-sofia.bg/index.php/fmi/article/view/203. Acesso em: 14 dec. 2025.