Reflections on refractions.
Reflections on spheres and cylinders of revolution.
Regular conditional linear spaces with two consecutive line degrees.
Regular hexagons associated to centroid sharing triangles.
Regular hexagons in normed spaces and a theorem of Walter Benz.
Regular hyperbolic fibrations.
Regular linear spaces.
Regular partial conical flocks.
Regular polygons
Regular polyhedra - old and new.
Regular Polyhedra - Old and New. (Short Communication).
Regular Polytopes from Twisted Coxeter Groups.
Regularity of algebras with applications to congruence class geometry
Regularly Derived Planes.
Reguli and chains over skew fields.
Rektifizierbare vierdimensionale Simplices.
Relationen zwischen Symmetrien in orthogonalen Gruppen.
Relationen zwischen symplektischen Transvektionen.
Relations entre les rayons de courbure de quelques systèmes de courbes
Relations on lines as primitive notions for Euclidean geometry