@article{10_37236_1332,
     author = {Doris Schattschneider},
     title = {Escher's combinatorial patterns},
     journal = {The electronic journal of combinatorics},
     year = {1997},
     volume = {4},
     number = {2},
     doi = {10.37236/1332},
     zbl = {0886.05047},
     url = {http://geodesic.mathdoc.fr/articles/10.37236/1332/}
}