Sudoku Solutions
As the puzzles get harder, you’ll need more techniques and methods to help solve them.
A Step-by-Step Guide To Solving Puzzles. Novice - 4x4 Puzzle
Beginners - 9x9 Puzzle
Ten Sudoku techniques to help you solve faster.
Intermediate to Advanced
Read the first chapter of Stefan Zweig's seminal book on the mental battle of chess here (Vietnamese only, sorry!)