Help me to find this magazine Some years ago I've read a mathematical magazine about pigeonhole principle. I love the structure of the magazine, first it explains about the subject and after it has a lot of interesting exercises about the same topic. Someone knows a mathematical magazine that has this structure?

I strongly recommend the math newsletter called Mathematical Excalibur edited by Kin-Yin Li (Department of Mathematics - The Hong Kong University).

It's free and the first issue is just about the Pigeonhole Principle. Each issue has a main topic.