Dividing a system into almost unidirectional blocks -- A linear algorithm for five-coloring a planar graph -- On the layering problem of multilayer PWB wiring -- A status on the linear arboricity -- On centrality functions of a graph -- Canonical decompositions of symmetric submodular systems -- The subgraph homeomorphism problem on reducible flow graphs -- Combinatorial problems on series-parallel graphs -- A graph-planarization algorithm and its application to random graphs -- Some common properties for regularizable graphs, edge-critical graphs and b-graphs -- "Dualities" in graph theory and in the related fields viewed from the metatheoretical standpoint -- On central trees of a graph -- On polynomial time computable problems -- Homomorphisms of graphs and their global maps -- Algorithms for some intersection graphs -- An efficient algorithm to find a Hamiltonian circuit in a 4-connected maximal planar graph -- Characterization of polyhex graphs as applied to chemistry -- The two disjoint path problem and wire routing design.