13.01.2010, 04:51
Sorry for writting in English.
I'm a Japanese Puzzler.
We have a puzzle site "Puzzle Generator Japan" http://puzzle.gr.jp/
In this site, there are many sudoku problems.
If you want very hard problems, plase visit the following page.
http://puzzle.gr.jp/show/English/NPProbl...endish-200
I hope you will enjoy them
I'm a Japanese Puzzler.
We have a puzzle site "Puzzle Generator Japan" http://puzzle.gr.jp/
In this site, there are many sudoku problems.
If you want very hard problems, plase visit the following page.
http://puzzle.gr.jp/show/English/NPProbl...endish-200
I hope you will enjoy them