%0 Journal Article %A V. HAVEL %T On Collineations on Three and Four Lines in a Projective Plane (Short Communication) %J Aequationes mathematicae %D 1969 %P 397-398 %V 2 %I mathdoc %U http://geodesic.mathdoc.fr/item/AM2_1969__2_182352/ %F AM2_1969__2_182352