- Tree-decompositions of graphs, lecture notes for the Catlin Memorial Workshop.
- Planarity in linear time, an exposition of a planarity algorithm of Shih and Hsu.

- Recent excluded minor theorems for graphs, invited lecture at the 17th British Combinatorial Conference
- Directed tree-width
- Transparencies for my talk at the Graph Drawing 99 conference and a proceedings version.
- Hadwiger's conjecture for K6-free graphs
- Linkless embeddings of graphs in 3-space
- Tree-decompositions of graphs
- Packing directed circuits
- Coloring graphs on surfaces
- The Strong Perfect Graph Theorem.
- Digraph Minors and Algorithms, an invited talk at the Eleventh Annual ACM-SIAM Symposium on Discrete Algorithms (SODA).
- The 2000 CIRM-DONET Workshop on Graph Theory and a tentative plan for my lectures there.
- The Four Color Theorem and a more recent addition, which is joint work with Serguei Norine.
- Slides for my talks at the Regional NSF-CBMS conference on Graph Structure and Decomposition
- Minicourse at the Euler institute for Discrete Mathematics and its Applications
- Large 6-connected graphs with no K_6 minor
- Pfaffian orientations of graphs, an invited 45 minute section talk at the International Congress of Mathematicians, Madrid, Spain, August 2006
- Coloring triangle-free graphs on surfaces
- A tutorial for the Fall School on Algorithmic Graph Structure Theory
- K_t minors in large t-connected graphs

- Configurations in large t-connected graphs
- Beyond Grotzsch's theorem