@article{JDM_1951__54_146344,
     author = {Frank L\"obell},
     title = {'Landkarten' der nichteuklidschen {Ebene.}},
     journal = {Jahresbericht der Deutschen Mathematiker-Vereinigung},
     pages = {4--23},
     publisher = {mathdoc},
     volume = {54},
     year = {1951},
     zbl = {0041.27402},
     url = {http://geodesic.mathdoc.fr/item/JDM_1951__54_146344/}
}