
The Times Ultimate Killer Su Doku Book 11: 200 of the Deadliest Su Doku Puzzles (The Times Su Doku)
The Times Ultimate Killer Su Doku Book 11: 200 of the Deadliest Su Doku Puzzles (The Times Su Doku)
www.amazon.co.jp/dp/0008285454/ref=asc_df_00082854541641054600000/