@article{SLC_1995_34_a12,
     author = {Mohamed El Marraki and Alexander Zvonkin},
     title = {Compositions des {Cartes} et {Hypercartes}},
     journal = {S\'eminaire lotharingien de combinatoire},
     publisher = {mathdoc},
     volume = {34},
     year = {1995},
     url = {http://geodesic.mathdoc.fr/item/SLC_1995_34_a12/}
}