Killer Sudoku, Difficulty 3

Puzzle 6666 Jan 29 January 2013
Puzzle 6676 Jan 31 January 2013
Puzzle 6681 Feb 1 February 2013
Puzzle 6691 Feb 3 February 2013
Puzzle 6701 Feb 5 February 2013
Puzzle 6711 Feb 7 February 2013
Puzzle 6721 Feb 9 February 2013
Puzzle 6730 Feb 11 February 2013
Puzzle 6740 Feb 13 February 2013
Puzzle 6750 Feb 15 February 2013
Daily Killer Sudoku