XU, XIRONG; YUANSHENG, YANG; MING, DI. Feedback vertex set of generalized de Bruijn digraphs GB(d,n). Utilitas Mathematica , [S. l.], v. 79, 2009. Disponível em: https://utilitasmathematica.com/index.php/Index/article/view/611. Acesso em: 8 may. 2026.