@article{JMPA_1940_9_19_1-4_221_0,
     author = {Birkhoff, George D.},
     title = {On drawings composed of uniform straight lines},
     journal = {Journal de Math\'ematiques Pures et Appliqu\'ees},
     pages = {221--236},
     publisher = {Gauthier-Villars},
     volume = {Ser. 9, 19},
     number = {1-4},
     year = {1940},
     zbl = {0024.28501},
     language = {en},
     url = {http://archive.numdam.org/item/JMPA_1940_9_19_1-4_221_0/}
}