On converses of Napoleon's theorem and a modified shape function.
On cyclic curves in the Euclidean n-space.
On Decomposititons of Discontinuous Groups of the Plane.
On Desargues geometrization of the characteristic of a skew field.
On Difference Matrices, Resolvable Transversal Designs and Generalized Hadamard Matrices.
On distance preserving transformations of Euclidean-like planes over the rational fields.
On distance preserving transformations of Euclidean-like planes over the rational fields. (Short Communication).
On distance preserving transformations of lines in Euclidean three-space.
On Dominating Sequences in the Unit Disc.
On Double Transitivity in Finite Affine Planes.
On elations in semi-transitive planes.
On equations and properties concerning some classes of chordal polygons.
On equilateral simplices in normed spaces.
On finite circular spaces.
On finite near-circular spaces.
On finite projective planes in Lenz-Barlotti class at least I.3.
On flag-transitive anomalous -geometries.
On flocks of infinite quadratic cones.
On four-colourings of the rational four-space.
On free constructions.