| IMO Problems: International Math Olympiad problems and solutions from 1959 to present, collected by John Scholes. |
| International Mathematical Talent Search: Solutions and Comments. |
| Internet Mathematics Contest Problems: Contest questions from the 1998 Douglas Zare's internet contest. |
| Kalva: Complete set of all International Mathematical Olympiad problems with solutions. Also includes problems sets from other national and international contests. |
| Kiran Kedlaya's Math Problem Directory: Sources of information about mathematical problem-solving. Focusing on long-answer type problems found on Olympiad-type contests or in problem sections of math journals. |
| Madras College Mathematics Department Resources: Problems from UK Math Olympiads and a collection of training materials. |
| Math Olympiad Problems from Around the World: In particular, from Iran. |
| Math Olympiads: Collection of problem sets from International and National Mathematics Olympiads. |
| Mathematics Problem Solving: Old sample problems from Putnam training sessions, by Monica Nevens (University of Ottawa). |
| Olympiad Math Madness: Jeffrey Lockshin's collection of mathematical problems, invented for mathematical olympiads all over the world. |
| Problem Page: Archive of problem sets and solutions from Wisconsin Mathematics, Engineering and Science Talent Search. |
| Problem Writing For Mathematics Competitions: Mathematics problems for middle school and high school math competitions with topics range from algebra and geometry to probability and trigonometry. |
| Prof. W. Kahan's Notes and Problems: Large archive of problems and solutions from Professor Kahan's Putnam Problems Practice Seminar. |
| Putnam Problem Solving: Supplementary problems and related links by Byungchul Cha (Johns Hopkins University). |
| Resources for the Putnam Mathematical Competition: Three sets of practice problems in PDF format compiled Yang Wang of Georgia Institute of Technology. |
| Singapore International Mathematics Olympiad: Training resources include problems and partial solutions. |
| The Putnam Mathematical Competition: Practice problems for Putnam competition in postscript and PDF format. Page organized by Harry Tamvakis (Brandeis). |
| Tournament of Towns at Toronto: Contest problems and solutions for The International Mathematics Tournament of the Towns. |
| Union College Putnam Club: Problem sets from weekly practice sessions. |
| USA, International and Asian Pacific Math Competitions Archive: Problems for the US Mathematical Olympiad (1989-2003), International Mathematical Olympiad (1986-2003), Asian Pacific Mathematical Olympiad, and the Team Selection Test. |
| USSR Math Olympiad, 1961-1986: Problems without solutions. |
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