@article{GDZPPN002378078, title = {On a principle of duality in circle sphere and line geometries}, journal = {Mathematische Zeitschrift}, volume = {45}, year = {1939}, pages = {185-194}, zbl = {64.0656.02}, url = {http://dml.mathdoc.fr/item/GDZPPN002378078} }
Rao, A. N.,. On a principle of duality in circle sphere and line geometries. Mathematische Zeitschrift, Tome 45 (1939) pp. 185-194. http://gdmltest.u-ga.fr/item/GDZPPN002378078/