1. N. Robertson and P. D. Seymour, Graph minors. II. Algorithmic aspects of tree-width, submitted.
2. N. Robertson and P. D. Seymour, Graph minors. III. Planar tree-width,J. Combinatorial Theory (Ser. B), to appear.
3. N. Robertson and P. D. Seymour, Graph minors. IV. Tree-width and well-quasiordering, submitted.
4. N. Robertson and P. D. Seymour, Graph minors. V. Excluding a planar graph, submitted.