@article{MZ_1967__100_170815,
     author = {Rolf Lingenberg},
     title = {Metrische {Ebenen} mit dreiseitverbindbaren {Punkten.} {I.}},
     journal = {Mathematische Zeitschrift},
     pages = {314--350},
     publisher = {mathdoc},
     volume = {100},
     year = {1967},
     zbl = {0153.49701},
     url = {http://geodesic.mathdoc.fr/item/MZ_1967__100_170815/}
}