Immersions of graphs into projective plane
Maxim A. Ivashkovskii · Moscow University Mathematics Bulletin · 2017
Immersions of graphs into the projective plane are studied. A classification of immersions up to a regular homotopy is obtained. A complete invariant of immersions up to a regular homotopy is constructed. The case of immersions of graphs into any compact surface differing from the projective plane was known previously.