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
Relative differential -characters.
Relativistische Mechanik mit klassicher Geometrie und Kinematik.
Remark about a construction of some tournaments points of certain projective planes
Remark on "Planes with analogues to Eucledian angular bisectors".
Remarks on a paper of Tallini
Remarks on projectivities.
Remarque sur un théorème de M. A. Pellissier
Remarques au sujet d'une note de M. Collignon
Replaceable nets and improper collineations
Representation and Construction of Projective Planes and Other Geometric Structures from Projective Spaces.