Includes bibliographical references.

Chromatic polynomials and mod lambda flows on directed graphs and their applications ; Four-coloring six-regular graphs on the torus ; On the complexity of a restricted list-coloring problem ; Totally critical graphs and the conformability conjecture ; Graphs whose radio coloring number equals the number of nodes ; The height and length of colour switching ; Characteristic polynomials in the theory of polyhedra ; The number of edge 3-colourings of the prism ; The cost of radio-colouring paths and cycles ; Restricted graph coloring: Some mathematical programming models