@article{MZ_1976__146_172302,
     author = {Herbert Abels and Annette Lauer},
     title = {A {Characterization} of the {Sphere} and {Euclidean} {Space} by {Transformation} {Groups.}},
     journal = {Mathematische Zeitschrift},
     pages = {137--142},
     publisher = {mathdoc},
     volume = {146},
     year = {1976},
     zbl = {0315.57029},
     url = {http://geodesic.mathdoc.fr/item/MZ_1976__146_172302/}
}