@article{GDZPPN002033062, title = {Subplane replacement in projective planes.}, journal = {Aequationes mathematicae}, volume = {22}, year = {1981}, pages = {134-139}, zbl = {0481.51009}, url = {http://dml.mathdoc.fr/item/GDZPPN002033062} }
Vedder, Klaus; Swart, Henda. Subplane replacement in projective planes.. Aequationes mathematicae, Tome 22 (1981) pp. 134-139. http://gdmltest.u-ga.fr/item/GDZPPN002033062/