@article{MZ_1971__122_171588,
     author = {Hansjoachim Groh},
     title = {1-Dimensional {Orbits} in {Flat} {Projective} {Planes.}},
     journal = {Mathematische Zeitschrift},
     pages = {117--124},
     year = {1971},
     volume = {122},
     zbl = {0207.19503},
     url = {http://geodesic.mathdoc.fr/item/MZ_1971__122_171588/}
}