Twisted Link Theory
  We introduce stable equivalence classes of oriented links in orientable three-manifolds that are orientation $I$-bundles over closed but not necessarily orientable surfaces. We call these twisted links, and show that they subsume the virtual knots introduced by L. Kauffman, and the projective links introduced by Yu. Drobotukhina. We show that these links have unique minimal genus three-manifolds. We use link diagrams to define an extension of the Jones polynomial for these links, and show that this polynomial fails to distinguish two-colorable links over non-orientable surfaces from non-two-colorable virtual links. 
Mario O. Bourgoin