This is an archived course. A more recent version may be available at ocw.mit.edu.
Neil Sloan's On-Line Encyclopedia of Integer Sequences
Richard Stanley's Enumerative Combinatorics Page
Richard Stanley's list of problems on Catalan Addendum
Information about Bona, M. A Walk through Combinatorics. 1st ed. Singapore, SG: World Scientific Publishing Company, 2002. ISBN: 9810249012.