Models of rubric: One-sided surfaces Model 294 Knitted Möbius strip Model 296 Boy's surface with three critical points Model 297 Boy's surface with symmetry axis Model 298 Three Möbius strips Model 299 Möbius strip Model 301 Heptahedron (one-sided surface) Model 346 Projective plane Model 347 Tetrahedron in the projective space Model 373 Boy's surface with symmetry axis Model 374 Möbius strip with a sphere as boundary curve Model 466 Eversion of the sphere