Puzzle string: 
        
    Sudoku
- Sudoku
 - Play Sudoku
 - Play Sudoku
 - Basic Strategies
 - Singles in Rows, Columns, and Blocks Strategy
 - Naked Pairs, Naked Triples, Naked Quads Strategy
 - Hidden Pairs, Hidden Triples, Hidden Quads Strategy
 - Pointing Pairs, Pointing Triples, Intersection Removal Strategy
 - Box/Line Reduction Intersection Removal Strategy
 - Advanced Strategies
 - X-Wing Strategy
 - Simple Coloring (Singles Chains) Strategy
 - Y-Wing Strategy
 - Rectangle Elimination
 - Swordfish Strategy
 - Challenging Strategies
 - X-Cycles Strategy
 - XY-Chain Strategy
 - 3D Medusa Strategy
 - Unique Rectangle Strategy
 - Hidden Unique Rectangle Strategy
 - XYZ-Wing Strategy
 - Utilities
 - Sudoku Solver - Unique or Multiple Solution Finder
 - Evaluate Sudoku Puzzle Difficulty - How easy or hard is it?
 
Thonky's Sudoku
- Table of Contents
 - Sudoku Main Page
 - Play Sudoku
 - Play Sudoku
 - Basic Strategies
 - Singles in Rows, Columns, and Blocks Strategy
 - Naked Pairs, Naked Triples, Naked Quads Strategy
 - Hidden Pairs, Hidden Triples, Hidden Quads Strategy
 - Pointing Pairs, Pointing Triples, Intersection Removal Strategy
 - Box/Line Reduction Intersection Removal Strategy
 - Advanced Strategies
 - X-Wing Strategy
 - Simple Coloring (Singles Chains) Strategy
 - Y-Wing Strategy
 - Rectangle Elimination
 - Swordfish Strategy
 - Challenging Strategies
 - X-Cycles Strategy
 - XY-Chain Strategy
 - 3D Medusa Strategy
 - Unique Rectangle Strategy
 - Hidden Unique Rectangle Strategy
 - XYZ-Wing Strategy
 - Utilities
 - Sudoku Solver - Unique or Multiple Solution Finder
 - Evaluate Sudoku Puzzle Difficulty - How easy or hard is it?