- Every math teacher I have ever had, especially Mr. Beach at Los Alamitos High School.
- The Grey Labyrinth for their problems.
- Richard Tucker for his solution to the first coin flipping problem and the shortest distance problem.
- Alan Curry for his solution to the two boats problem.
- Dr. Chuan-Ming Zou for his solution to the flying bird problem.
- The
*Actuarial Review*for the snowplow problem and the nursery problem. - The puzzle page of Guy de Kindler for his problems.
- Dylan Thurston, for the second coin flipping problem.
- A Usenet archive for various problems.
- Marilyn Vos Savant for problem 78.
- The Eisenhower National Clearinghouse for Mathematics and Science Education. They listed this page in their Digital Dozen.
- The Ultimate Puzzle Site for the pirate problem.
- Igor Volkov for the solution to the mean distance problem.
- Antonio Cordoba for problem 95.
- Steven Lutz for the dog/lighthouse problem.
- Nick Hobson for Problem 68, 99, and 119.
- Alon Amit for Problem 127.
- Steve Schaefer has been kindly volunteered to be a guinea pig for new problems before I add them to the site. Please visit his own math site >Mathematical Recreations. He also likes practical math problems from everyday life.

- The Web Wizard's Math Challenge. Seven tough problems you can solve for points, my total is 1095.
- Mathematics Problems and Warm-ups. 101 math problems with solutions, ideal for someone with a high school level background in math.
- For over 200 math problems visit The Math Archive.
- Vist Brian Storm for more math problems.
- Ole Miss geometry problem of the week.
- Freelearning.com. A nice web page by a math teacher devoted to learning more on a host of subjects including math.
- The Contest Center. Lots of problems, grouped by category.
- Nick's Mathematical Puzzles. About 50 math problems with hints and solutions.
- MathProblems.tv. Videos of easy math problems and solutions.