@article{MZ_1937__42_168720,
     author = {H., G\"ortler},
     title = {Zur {Addition} beweglicher ebener {Eibereiche}},
     journal = {Mathematische Zeitschrift},
     pages = {313--321},
     publisher = {mathdoc},
     volume = {42},
     year = {1937},
     zbl = {63.0672.03},
     url = {http://geodesic.mathdoc.fr/item/MZ_1937__42_168720/}
}