Regular conditional linear spaces with two consecutive line degrees.
Semiaffine spaces.
Some Generalization of Nearaffine Planes
There are three kinds of Benz planes: Möbius planes, Laguerre planes and Minkowski planes. A Minkowski plane satisfying an additional axiom is connected with some other structure called a nearaffine plane. We construct an analogous structure for a Laguerre plane. Moreover, our description is common for both cases.
Subplane replacement in projective planes.
Teilmengengraphen und projektive Räume.
The classification of subplane covered nets.
The elementary geometry of a triangular world with hexagonal circles.
The generating rank of the symplectic line-Grassmannian.
The Skew-Hyperbolic Motion Group of the Quaternion Plane.
The universal embedding of the near polygon .
The valuations of the near polygon G.
Topological and smooth unitals.
Two theorems on homomorphism of projective nets
Über das Verhalten des Ranges bei der Erweiterung von Inzidenzstrukturen.
Über die Eigenschattengrenze hermitischer Quadriken.
Über die Typen der A-Systeme.
Über ein gewisses Netz ebener Kurven 6. Ordnung
Über eine Eigenschaft von Ovalen
Über projektive Ebenen des Lenz-Barlott-Typs I.3.
Über projektive Erweiterung affiner Klingenbergscher Ebenen