Non-orientable one dimensional manifold.
99755
Non-orientable 1-dimensional (non-hausdorff) manifold
123430
Can a topological manifold be non-connected and each component with different dimension?
70223
Inducing orientations on boundary manifolds
153054
Euler characteristic for non-convex polyhedra.
84419
Product of manifolds & orientability
67805
Why is fundamental group insufficient to classify manifolds?
26379
What is non-manifold geometry?
101418
Can we define flat connection on any given smooth manifold?
137342
Can spacetime be non-orientable?
154009
Closed, simply connected manifolds which are not spheres
132382
Showing a set is nowhere dense in $C([0,1])$
82989
T4 and first countable topology that is non metrizable
71791
Smooth structure of embedded submanifolds
121495
Decompose vector fields on product manifolds
5303
isolated non-normal surface singularity
79922
Orientation reversing diffeomorphism
66770
Intuition for Smooth Manifolds