@article{SLC_1989_22_a6,
     author = {Luigi Cerlienco and Francesco Piras},
     title = {Sulla blalgebra duale della bialgebra dei polinomi in pi\`u variabili},
     journal = {S\'eminaire lotharingien de combinatoire},
     publisher = {mathdoc},
     volume = {22},
     year = {1989},
     url = {http://geodesic.mathdoc.fr/item/SLC_1989_22_a6/}
}