Journal of Combinatorial Theory, Series B, Volume 70
Volume 70, Number 1, May 1997
Special Issue Dedicated to W. T. Tutte. 1
László Lovász: The Membership Problem in Jump Systems. 45-66
Carsten Thomassen: Color-Critical Graphs on a Fixed Surface. 67-100
James F. Geelen: A Generalization of Tutte's Characterization of Totally Unimodular Matrices. 101-117
David B. Massey, Rodica Simion, Richard P. Stanley, Dirk L. Vertigan, Dominic J. A. Welsh, Günter M. Ziegler: Lê Numbers of Arrangements and Matroid Identities. 118-133
Maurits de Graaf, Alexander Schrijver: Making Curves Minimally Crossing by Reidemeister Moves. 134-156

Paul D. Seymour: Two Chromatic Polynomial Conjectures. 184-196

Volume 70, Number 2, July 1997
Zdenek Ryjácek: On a Closure Concept in Claw-Free Graphs. 217-224
Bing Zhou: Some Theorems Concerning the Star Chromatic Number of a Graph. 245-258
J. Arias de Reyna: Finite Fields and Ramanujan Graphs. 259-264
Atsuhiro Nakamoto, Katsuhiro Ota: Diagonal Transformations of Graphs and Dehn Twists of Surfaces. 292-300
Péter Komjáth: Two Remarks on the Coloring Number. 301-305
Carsten Thomassen: A Simpler Proof of the Excluded Minor Theorem for Higher Surfaces. 306-311
Stéphanie Conilh: Note on Kocay's 3-Hypergraphs and Stockmeyer's Tournaments. 312-316
Thomas Zaslavsky: The Largest Parity Demigenus of a Simple Graph. 325-345
Artur Andrzejak: Splitting Formulas for Tutte Polynomials. 346-366



