@article{VM_2004_6_1_a1,
     author = {Carlos E. Puente and Marta G. Puente},
     title = {Ice {Crystals} {Inside} the {Bell}},
     journal = {Visual Mathematics},
     publisher = {mathdoc},
     volume = {6},
     number = {1},
     year = {2004},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/VM_2004_6_1_a1/}
}