@article{JDM_1931__40_145877,
     author = {Ernst Lammel and Karl Carda},
     title = {Eine {Eigenschaft} des regelm\"a{\ss}igen {Siebenecks.}},
     journal = {Jahresbericht der Deutschen Mathematiker-Vereinigung},
     pages = {107--108},
     publisher = {mathdoc},
     volume = {40},
     year = {1931},
     zbl = {0001.15503},
     url = {http://geodesic.mathdoc.fr/item/JDM_1931__40_145877/}
}