4-dimensionale Translationsebenen mit kommutativer Standgruppe.
types of configurations of flexes and sextactic points of a cubic
A 2-metric Characterization of the Euclidean Plane.
A Beckmann Quarles Type Theorem for Plane Lorentz Transformations.
A case of the 3-dimensional problem of Appollonius.
A characteristic property of orthogonal pencils of coaxal circles from the standpoint of conformal mapping
A characterization of all equilateral triangles in .
A characterization of compact convex polyhedra in hyperbolic 3-space.
A characterization of compact convex polyhedra in hyperbolic 3-space (Corrigendum).
A characterization of continuous associative operations whose graphs are ruled surfaces.
A Characterization of Motions as Bijections Preserving Inradius or Circumradius One.
A characterization of regular saddle surfaces in the hyperbolic and spherical three-space.
A characterization of spheres among compact 3-bodies satisfying Crofton's theorem
A characterization of the Desarguesian planes of order by .
A characterization of the Grassmannian of points and lines for -buildings.
A characterization of the Hall planes by planar and nonplanar involutions.
A Characterization of the Lüneburg Planes.
A class of Buekenhout unitals in the Hall plane.
A class of complete arcs in multiply derived planes.
A class of inequalities related to the angle bisectors and the sides of a triangle.