@article{VM_2007_9_1_a1,
     author = {Izidor Hafner},
     title = {Animated {Proof} of {Conway-Radin-Sadun} {Problem}},
     journal = {Visual Mathematics},
     publisher = {mathdoc},
     volume = {9},
     number = {1},
     year = {2007},
     url = {http://geodesic.mathdoc.fr/item/VM_2007_9_1_a1/}
}