Curves and solids of constant width
Peaucellier–Lipkin inversor
Singularities and reversing elements of space curves
Tangent developable of a quartic space curve
Ruled surfaces of degree 4 by Rohn
Singularity in the origin
Envelopes of surface normals
Accompanying ruled surfaces
Extremal polyhedra by Brehm
Minimal polyhedra by Brehm
Confocal Quadrics and focal conics
Krümmung in einem Flächenpunkt
Kartonmodelle von Flächen 2. Ordnung
Brill/Schilling, Series 1
Brill/Schilling, Series 3
Brill/Schilling, Series 2
Brill/Schilling, Series 4
Brill/Schilling, Series 5
Brill/Schilling, Series 3