@article{VM_2011_13_2_a1,
     author = {Ali Deniz and Sahin Kocak and Ynuns Ozdemir and A. Ersin Ureyen},
     title = {Wallpaper {Patterns} with {Self-Similar} and {Graph-Directed} {Fractal} {Lattice} {Units}},
     journal = {Visual Mathematics},
     publisher = {mathdoc},
     volume = {13},
     number = {2},
     year = {2011},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/VM_2011_13_2_a1/}
}