@article{SLC_1990_24_a0,
     author = {Guoniu Han},
     title = {Escaliers \'evalu\'es et nombres classiques},
     journal = {S\'eminaire lotharingien de combinatoire},
     publisher = {mathdoc},
     volume = {24},
     year = {1990},
     url = {http://geodesic.mathdoc.fr/item/SLC_1990_24_a0/}
}