@article{SLC_2001-2002_47_a4,
     author = {Guo-Niu Han and Dominique Perrin},
     title = {Ensembles in\'evitables},
     journal = {S\'eminaire lotharingien de combinatoire},
     year = {2001-2002},
     volume = {47},
     url = {http://geodesic.mathdoc.fr/item/SLC_2001-2002_47_a4/}
}