copyright

• Publication right to problems are reserved by the original publishers. When citing problems, only orginal sources should be listed
The following publishers have  granted permission to reprint problems here;

1. The international mathematical olympiad
2. problems corner.org( Founded by MathPro and the Department of mathematical and Staistics of the university of Missouri- Rolla
3. the Canadian mathematical society (Crux Mathematicorum  with Mayhem)
4. KAIST(Korea Advanced Institute of Science and Technology) ,Marthematical problem solving Group