@article{DMGT_2014_34_3_a0,
     author = {Galeana-S\'anchez, H. and Hern\'andez-Cruz, C.},
     title = {On the existence of (\protect\emph{k},\protect\emph{l})-kernels in infinite digraphs: {A} survey},
     journal = {Discussiones Mathematicae. Graph Theory},
     pages = {431--466},
     publisher = {mathdoc},
     volume = {34},
     number = {3},
     year = {2014},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/DMGT_2014_34_3_a0/}
}