51Hxx Topological geometry
- 51H05 General theory (2)
- 51H10 Topological linear incidence structures
- 51H15 Topological nonlinear incidence structures
- 51H20 Topological geometries on manifolds [See also 57-XX]
- 51H25 Geometries with differentiable structure [See also 53Cxx, 53C70]
- 51H30 Geometries with algebraic manifold structure [See also 14-XX]
- 51H99 None of the above, but in this section