Surfaces Genus (mathematics) Klein bottle Real projective plane Boy's surface Roman surface Steiner surface Möbius strip Cross-cap Knot theory Unknot Prime knot Crossing number Loop (knot) List of loop knots Figure-eight knot (mathematics) Trefoil knot Knot invariant Knot polynomial Alexander polynomial Jones polynomial Skein relation Braid theory Manifolds Orientable manifold Haken manifold Jaco-Shalen-Johannson torus decomposition Poincaré conjecture Thurston elliptization conjecture Thurston's Geometrization Conjecture
