ERFANG, SHAN; LIYING, KANG; QIN, LU. K-semikernels, k-quasikernels, k-kernels in digraphs and their line digraphs. Utilitas Mathematica , [S. l.], v. 72, 2007. Disponível em: https://utilitasmathematica.com/index.php/Index/article/view/502. Acesso em: 8 may. 2026.