Puzzles and problems

Puzzles and Problems
 ** ONGELMIA - pientä ja suurta purtavaa
 ** Berkeley Preliminary Exams
 ** Brain Teasers
 ** College Problems of the Week 
 ** Conjectures in Geometry
 ** Exercise your brain
 ** Interactive Mathematics Miscellany and Puzzles
 ** MathPro Press
 ** Period Com Puzzles
 ** Problem of the Week
 ** Problem Solving Task Centres - PSTC
 ** Puzzle Corner
 ** Solmu - Matematiikkaa harrastaville suunnattu lehti
 ** The MathCad Puzzles
 ** The Sphinx Puzzles
 ** Unsolved Mathematics Problems
 ** Virtual Geometry Problems