25 x 25 Large Sudoku Solving Hints

Strategy tips for the massive 25 x 25 sudoku magazine: how to tackle these daunting puzzles

Glossary of Sudoku - Wikipedia

The Ultimate Sudoku Strategy Guide

How To Play Sudoku: The Ultimate Guide to Beating Any Puzzle - TCK Publishing

Alphadoku image example, 25X25 sudoku puzzle, asymmetric, expert No. 10000.

A Sudoku with 17 clues and its unique solution.

Solving Sudoku by Heuristic Search, by David Carmel

Solving Sudoku by Heuristic Search, by David Carmel

The Ultimate Sudoku Strategy Guide

25 x 25 Large Sudoku Solving Hints

Making and Slaying Monster Sudoku