Akari

American Republic

Anti Diagonal Sudoku

Binary

Binary Puzzles

Calcudoku

Calcudoku Puzzles

Chain Sudoku

Consecutive Sudoku

Cross Sudoku

Expert's Voice in Open Source

Futoshiki

Futoshiki Puzzles

GCSE Success Essentials S.

Hacking Exposed

Hard Puzzles Book

Hashi

Heyawake Puzzles

Hidoku

Hitori