@article{VM_1999_1_4_a1,
     author = {Ljubi\v{s}a M. Koci\'c},
     title = {Portraits of {Numbers}},
     journal = {Visual Mathematics},
     publisher = {mathdoc},
     volume = {1},
     number = {4},
     year = {1999},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/VM_1999_1_4_a1/}
}