@article{DMGT_2009_29_1_a2,
     author = {Galeana-Sanchez, Hortensia and Pastrana, Laura},
     title = {k-Kernels and some operations in digraphs},
     journal = {Discussiones Mathematicae. Graph Theory},
     pages = {39--49},
     publisher = {mathdoc},
     volume = {29},
     number = {1},
     year = {2009},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/DMGT_2009_29_1_a2/}
}