James G. Oxley, Geoff Whittle. Tuttle invariants for 2-polymatroids. In Neil Robertson, Paul D. Seymour, editors, Graph Structure Theory, Proceedings of a AMS-IMS-SIAM Joint Summer Research Conference on Graph Minors held June 22 to July 5, 1991, at the University of Washington, Seattle. Volume 147 of Contemporary Mathematics, pages 9-20, American Mathematical Society, 1991.
Abstract is missing.