@article{GDZPPN00239331X, title = {Elations of finite projective planes.}, journal = {Mathematische Zeitschrift}, volume = {82}, year = {1963}, pages = {247-258}, zbl = {0114.12603}, url = {http://dml.mathdoc.fr/item/GDZPPN00239331X} }
Piper, F.C. Elations of finite projective planes.. Mathematische Zeitschrift, Tome 82 (1963) pp. 247-258. http://gdmltest.u-ga.fr/item/GDZPPN00239331X/