Links

Bibliographic tools

• MathSciNet
• CiteSeerX
• ACM Portal
• CCSB
• Google Scholar
• ArXiv

General reference

• MathWorld
• Integer Sequences

Computational catalogues

• A compendium of NP optimization problems
• Graph Template Library
• Combinatorial Object Server

Other combinatorial centres (deliberately incomplete)

• Cambridge, Queen Mary, LSE, British Combinatorial Committee (list of combinatorics in Britain)
• ETH Zürich, Carnegie Mellon, DIMACS, McGill, Waterloo

Conference listings

• British Combinatorial Committee
• Jan van den Heuvel
• Doug West
• Graph Theory and Combinatorics (at the Conference Management System)
• Janos Pach's Conference List

Miscellaneous

• The Erdos Number Project.