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