394 books • 40 series
Book of Sudoku Variants - Jigsaw Sudoku, Killer Sudoku, Tripod Sudoku, Sudoku X - 200 Easy Puzzles Book 1 (Book of Sudoku Variants, #1)
Book of Sudoku Variants - Suguru, Futoshiki, Binary, Numbricks, CalcuDoku - 200 Hard Puzzles Book 4 (Book of Sudoku Variants, #4)
Book of Sudoku Variants - Jigsaw Sudoku, Killer Sudoku, Tripod Sudoku, Sudoku X - 200 Hard Puzzles Book 2 (Book of Sudoku Variants, #2)
Book of Sudoku Variants - Suguru, Futoshiki, Binary, Numbricks, CalcuDoku - 200 Easy Puzzles Book 3 (Book of Sudoku Variants, #3)