The Times SAMURAI Su DOKU: 100 puzzles including super difficult: challenging from (The Doku)

The Times Difficult Su Doku: 200 challenging puzzles from (The Doku)

The Times Samurai Su Doku 4: 100 challenging puzzles from (The Doku)

The Times Samurai Su Doku 5: 100 challenging puzzles from (The Doku)

The Times Difficult Su Doku Book 6: 200 challenging puzzles from (The Doku)