A characterization of the Desarguesian planes of order by .
A geometrical characterization of the projective plane of order
About projective planes over weakly distributive skew-fields and systems.
An axiom system for the class of groups of dilatations in Fano-Pappian affine planes
Büschel in äquiaffinen Räumen
Central Automorphisms of Veblenian Nearaffine Planes
The paper deals with nearaffine planes described by H. A. Wilbrink. We consider their central automorphisms, i.e. automorphisms satisfying the Veblen condition, which become central collineations in connected projective planes. Moreover, a concept of central pseudo-automorphism is considered, i.e. some bijections in a nearaffine plane are not automorphisms but they become central collineations in the related projective planes.
Constructive Coordinatization of Desarguesian Planes.
Coordinate free definitions of cross ratio.
Der Satz von v. Staudt-Schleiermacher in Minkowski-Ebenen.
Durch Kollineationsgruppen bestimmte projektive Räume
Ein gruppentheoretischer Aufbau der räumlichen äquiaffinen Geometrie unter Verwendung von Scherungen
Eine Verallgemeinerung des Satzes von Dandelin.
Elementary versions of the Sylvester-Gallai theorem.
Entartete Steinerkegelschnitte in nichtpapposschen Desarguesebenen.
Extending Nearaffine Planes to Hyperbola Structures
H. A. Wilbrink [Geom. Dedicata 12 (1982)] considered a class of Minkowski planes whose restrictions, called residual planes, are nearaffine planes. Our study goes in the opposite direction: what conditions on a nearaffine plane are necessary and sufficient to get an extension which is a hyperbola structure.
Extension of Collineations Defined on Certain Sets of a Desarguesian Projective Plane
Flocks in PG(3, q).
Gruppentheoretische Charakterisierungen klassischer desarguesscher und moultonscher Ebenen.
Gruppentheoretische Kennzeichnung Pappusscher affiner Ebenen von Charakteristik ... 2.
Homogene 4-dimensionale affine Ebenen.