@article{VM_2000_2_1_a3,
     author = {R. P\'erez-G\'omez and Ceferino Ruiz},
     title = {Methods of {Perfect} {Coloring}},
     journal = {Visual Mathematics},
     publisher = {mathdoc},
     volume = {2},
     number = {1},
     year = {2000},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/VM_2000_2_1_a3/}
}