Putnam Training and Resources
- Art of Problem Solving (AoPS) Putnam Forum
- Herbert S. Wilf: Generatingfunctionology
- Previous Selection and Training Tests
- Northwestern Problem Solving Group
Collections of Problems
- Paul Zeitz: The Art and Craft of Problem Solving, John Wiley & Sons, Inc., 1999.
- Arthur Engel: Problem-Solving Strategies, Springer, 1998.
- Further bibliography on problem solving