@article{VM_2008_10_1_a2,
     author = {Izidor Hafner},
     title = {Gerling's dissection},
     journal = {Visual Mathematics},
     publisher = {mathdoc},
     volume = {10},
     number = {1},
     year = {2008},
     url = {http://geodesic.mathdoc.fr/item/VM_2008_10_1_a2/}
}