Maciej Liskiewicz Mitsunori Ogihara Seinosuke Toda The complexity of counting self-avoiding walks in subgraphs of two-dimensional grids and hypercubes. 129-156 2003 1-3 Theor. Comput. Sci. 304 http://dx.doi.org/10.1016/S0304-3975(03)00080-X db/journals/tcs/tcs304.html#LiskiewiczOT03