Robert L. Hemminger Heinz Adolf Jung On <i>n</i>-skein isomorphisms of graphs. 103-111 1982 32 J. Comb. Theory, Ser. B 2 http://dx.doi.org/10.1016/0095-8956(82)90027-2 db/journals/jct/jctb32.html#HemmingerJ82