Combinatorics Open Problems

• Josh Cooper's Math Pages : Open Combinatorics Problems  - Background information about the author and his email address. With papers and preprints.
• Open Problems in Combinatorics  - Provides information about the authors and their different combinatoric problem topics.
• Past Open Problems  - Presents searchable archive system for pre-publications. With a group newsletter in discrete mathematics.
• Problems in Graph Theory and Combinatorics  - Contains information about the resource for research in graph theory and combinatorics. With contributions and collections of the authors.
• Some Problems in Matroid Theory  - Contains problems found by the author, with samples for illustration. Includes sources and contact information.