@article{VM_1999_1_4_a2,
     author = {Michael Leyton},
     title = {Group {Theory} and {Architecture,} 2: {Why} {Symmetry/Asymmetry?}},
     journal = {Visual Mathematics},
     publisher = {mathdoc},
     volume = {1},
     number = {4},
     year = {1999},
     url = {http://geodesic.mathdoc.fr/item/VM_1999_1_4_a2/}
}