KHACHATURYAN, A. . Necessary Conditions for Optimal Permissible Placement by the Height of the Transitive Directed Tree with One Root. Mathematical Problems of Computer Science, [S. l.], v. 36, p. 104–114, 2021. Disponível em: http://93.187.165.2/index.php/mpcs/article/view/272. Acesso em: 28 sep. 2024.