A lower bound for the number of vertices of some Ramsey graphs. Annual of Sofia University St. Kliment Ohridski. Faculty of Mathematics and Informatics, [S. l.], v. 86, n. 1, p. 11–25, 1994. Disponível em: https://annual.uni-sofia.bg/index.php/fmi/article/view/430. Acesso em: 18 dec. 2025.