Discrete Mathematics Volume 244, Numbers 1-3, 6 February 2002 Contents Preface S. Klavzar, D. Marusié and B. Mohar Contributions D. Archdeacon and F. Sagols Nesting points in the sphere B. Bresar The direct expansion of graphs R.C. Brewster and P. Hell Homomorphisms to powers of digraphs M. Deza and M. Shtogrin Isometric embedding of mosaics into cubic lattices H. Enomoto, K. Ohba, K. Ota and J. Sakamoto Choice number of some complete multi-partite graphs X.G. Fang, C.H. Li, J. Wang and M.Y. Xu On cubic Cayley graphs of finite simple groups H. Fleischner Bipartizing matchings and Sabidussi’s compatibility conjecture A. Gutiérrez and A.S. Llado Regular packings of regular graphs H. Harborth Special numbers of crossings for complete graphs F. Havet and J. Zerovnik Finding a five bicolouring of a triangle-free subgraph of the triangular lattice M. Hirasaka and M. Muzychuk Association schemes generated by a non-symmetric relation of valency 2 M. Hladnik, D. Marusié and T. Pisanski Cyclic Haar graphs K.T. Huber and V. Moulton The relation graph R. Jajcay and J. Sirah Skew-morphisms of regular Cayley maps A. Jurisié and J. Koolen Krein parameters and antipodal tight graphs with diameter 3 and 4 R.B. King Novel highly symmetrical trivalent graphs which lead to negative curvature carbon and boron nitride chemical structures S. Kitakubo and S. Negami Re-embedding structures of 5-connected projective-planar graphs S. Klavzar, A. Lipovec and M. Petkovsek On subgraphs of Cartesian product graphs M. Kobeissi and M. Mollard Spanning graphs of hypercubes: starlike and double starlike trees A. Kotlov Matchings and Hadwiger’s Conjecture O. Kovarik, M. Mulaé and Z. Ryjacek A note on degree conditions for hamiltonicity in 2-connected claw-free graphs C.C. Lindner and L. Milazzo Embedding partial bipartite directed cycle systems C.H.C. Little, F. Rendl and |. Fischer Towards a characterisation of Pfaffian near bipartite graphs A. Malnic Action graphs and coverings J. Marinéek and B. Mohar On approximating the maximum diameter ratio of graphs D. Marusié and P. Potoénik Classifying 2-arc-transitive graphs of order a product of two primes B. Mohar Coloring Eulerian triangulations of the projective plane A. Nakamoto and S. Negami Generating triangulations on closed surfaces with minimum degree at least 4 L. Petingi and J. Rodriguez A new technique for the characterization of graphs with a maximum number of spanning trees M. Petkovsek Letter graphs and well-quasi-order by induced subgraphs T. Pisanski, T.W. Tucker and B. Zgrablic Strongly adjacency-transitive graphs and uniquely shift-transitive graphs N. Polat On isometric subgraphs of infinite bridged graphs and geodesic convexity P. Potoénik On 2-arc-transitive Cayley graphs of Abelian groups M. Razpet A self-similarity structure generated by king’s walk M. Sajna On decomposing K,, — / into cycles of a fixed odd length B. Servatius and H. Servatius A polynomial time algorithm for determining zero Euler-Petrie genus of an Eulerian graph T. Slivnik The exact isoperimetric inequality for ternary and quaternary cubes C. Tardif and X. Zhu The level of nonmultiplicativity of graphs M. Voigt and H. Walther Polyhedral graphs with restricted number of faces of the same type A.T. White Modelling finite geometries on surfaces B. Zgrablic On quasiabelian Cayley graphs and graphical doubly regular representations S. Zhou Imprimitive symmetric graphs, 3-arc graphs and 1-designs A. Zitnik Plane graphs with Eulerian Petrie walks B. Zmazek and J. Zerovnik Unique square property and fundamental factorizations of graph bundles Author index to volume 244