Vollmerhaus, W.Thompson, D.J.2008-02-262008-02-261980-12-01http://hdl.handle.net/1880/45681This paper presents some initial work done in establishing a complete list of irreducible non-embeddable graphs for the projective plane. The main result presented is the following theorem: All irreducible non-embeddable graphs for the projective plane which have a subgraph contractable to $GAMMA sub 1$ and do not have a subgraph contractable to $K sub 3,4$, are contractable to one of four graphs listed in the set $S sub 2$.EngComputer Scienceunknown1980-48-610.11575/PRISM/31107