X-Wings and the Rectangle Rule for Solving Medium to Hard Sudoku Puzzles

Book: Pocket Puzzles - Hard Sudoku (large print).

Book: Pocket Puzzles - Very Hard Sudoku (large print).

Large Print SUDOKU Puzzles: 100+ Easy to Hard Puzzles - Train your brain anywhere, anytime - Vol.2

Hidden Pairs a.k.a. Hidden Matching Pairs – Solving a More Difficult Puzzle

Sudoku Puzzle Book Large Print Volume.1- Easy Medium And Hard Levels

Triplets (a.k.a Triples) and Hidden Triplets Explained - A Sudoku Strategy You MUST Know

Tutorial #40 A must know technique. NOT a puzzle.

Extreme Sudoku

110 Hard to Extreme Sudoku Book Extra Large Print Format for Seniors- VOLUME 1 - Julian Falcon Books

Sudoku Solver - Explained Squiggly Sudoku Hard Sudoku

Sudoku Solver - How to Play Sudoku X Very Easy #8

Sudoku Primer 252 - Hard Sudoku - Subscriber Puzzle

Sudoku Solver - How to Play Sudoku X Very Easy #4

Sudoku Primer 242 - Unraveling a New York Times Hard Sudoku Puzzle

Sudoku Solver - Sudoku Easy Puzzle With Answers #8

Sudoku Solver - How to Play Sudoku X Easy #6

Sudoku Solver - Sudoku Easy Puzzle With Answers #3

Large Print SUDOKU Puzzles Book: 100+ Easy to Hard Puzzles - Train your brain anywhere, anytime!

Sudoku Book for Seniors HARD TO EXTREME Level - VOLUME 1 #sudokupuzzles #sudokubook