Discrete Mathematics

Editor-in-Chief: Douglas B. West University of Illinois at Urbana-Champaign, Urbana, USA, Managing Editor: Wayne Goddard Clemson University, Clemson, SC, USA, Associate Editors: P. Dukes University of Victoria, Victoria, BC, Canada, D. Král Charles University in Prague, Prague, Czech Republic, B. Mohar Simon Fraser University, Burnaby, BC, Canada, D. Osthus University of Birmingham, Birmingham, UK, I. Pak University of Minnesota, Minneapolis, MN, USA, O. Pikhurko Carnegie Mellon University, Pittsburgh, PA, USA, K. Rosen Monmouth University, W. Long Branch, NJ, USA, M. Schacht Universität Hamburg, Hamburg, Germany, D.R. Stinson University of Waterloo, Waterloo, ON, Canada, Advisory Editors: A.J. Hoffman IBM Thomas J. Watson Research Center, Yorktown Heights, NY, NY, USA, R.C. Mullin University of Waterloo, Waterloo, ON, Canada, V.T. Sós Hungarian Academy of Sciences, Budapest, Hungary, Board of Editors: M.S. Aigner Freie Universität Berlin, Berlin, Germany, B. Alspach University of Newcastle (New South Wales), Callaghan, NSW, Australia, G.E. Andrews Pennsylvania State University, University Park, PA, USA, A. Barlotti Università degli Studi di Firenze, Firenze, Italy, J.-C. Bermond Institut National de Recherche en Informatique et en Automatique (INRIA), Sophia-Antipolis, France, B. Bollobás University of Memphis, Memphis TN, USA, R.A. Brualdi University of Wisconsin at Madison, Madison, USA, P.J. Cameron Queen Mary, University of London (QMUL), London, UK, P. Camion Domaine de Volucean-Rocquencourt, Le Chesnay, France, G. Chartrand Western Michigan University, Kalamazoo MI, USA, V. Chvátal Concordia University, Montréal, QC, Canada, C.J. Colbourn Arizona State University, Tempe, USA, D. Foata Université Louis Pasteur (Strasbourg I), Strasbourg, France, A.S. Fraenkel Weizmann Institute of Science, Rehovot, Israel, P. Frankl Peter Frankl Office Ltd., Shibuya-Ku, Japan, A.M. Frieze Carnegie Mellon University, Pittsburgh, PA, USA, I. Gessel Brandeis University, Waltham MA, USA, R.L. Graham University of California at San Diego (UCSD), La Jolla, CA, USA, A. Hajnal Rutgers University, Piscataway, NJ, USA, J. Kahn Rutgers University, Piscataway, NJ, USA, G.O.H. Katona Hungarian Academy of Sciences, Budapest, Hungary, D.J. Kleitman Massachusetts Institute of Technology (MIT), Cambridge, MA, USA, A.V. Kostochka University of Illinois at Urbana-Champaign, Urbana, USA, P. Leroux Université du Quebec à Montreal (UQAM), Montreal QC, Canada, L. Lovász Microsoft Research, Redmond WA, USA, D. Marusic University of Ljubljana, Ljubljana, Slovenia, A. Rosa McMaster University, Hamilton, Canada, I. Rosenberg Université de Montréal, Montreal, QC, Canada, H. Sachs Technische Universität Ilmenau, Ilmenau, Germany, J. Schonheim Tel Aviv University, Tel Aviv, Israel, N.J.A. Sloane AT&T Research, Florham Park, NJ, USA, C. Thomassen Danmarks Tekniske Universitet (DTU), Lyngby, Denmark, W.T. Trotter Arizona State University, Tempe, AZ, USA, R. Wille Technische Universität Darmstadt, Darmstadt, Germany