@article{GDZPPN002410818, title = {A Characterization of the L\"uneburg Planes.}, journal = {Mathematische Zeitschrift}, volume = {129}, year = {1972}, pages = {82-90}, zbl = {0229.50028}, url = {http://dml.mathdoc.fr/item/GDZPPN002410818} }
Liebler, Robert. A Characterization of the Lüneburg Planes.. Mathematische Zeitschrift, Tome 129 (1972) pp. 82-90. http://gdmltest.u-ga.fr/item/GDZPPN002410818/