Thom Sulanke Frank H. Lutz Isomorphism-free lexicographic enumeration of triangulated surfaces and 3-manifolds. 1965-1979 2009 30 Eur. J. Comb. 8 http://dx.doi.org/10.1016/j.ejc.2008.12.016 db/journals/ejc/ejc30.html#SulankeL09