W. H. Tutte's 1947 paper on a ring generated by graphs satisfying a contraction-deletion relation is extended to ribbon graphs. This ring of ribbon graphs is a polynomial ring on an infinite set of one-vertex ribbon graphs.
Prof. Neal W. Stoltzfus, Department of Mathematics, Louisiana State University
Thompson, Daniel C.
"The Structure of the Tutte-Grothendieck Ring of Ribbon Graphs,"
Rose-Hulman Undergraduate Mathematics Journal: Vol. 13
, Article 2.
Available at: http://scholar.rose-hulman.edu/rhumj/vol13/iss2/2