@article{VM_1999_1_3_a1,
     author = {Peter Hilton and Jean Pedersen},
     title = {On the {Geometry} and {Combinatorics} of the {Array} of {Multinomial} {Coefficients}},
     journal = {Visual Mathematics},
     publisher = {mathdoc},
     volume = {1},
     number = {3},
     year = {1999},
     url = {http://geodesic.mathdoc.fr/item/VM_1999_1_3_a1/}
}