Killer Sudoku, Difficulty 10

Puzzle 5122 Mar 27 March 2012
Puzzle 5127 Mar 28 March 2012
Puzzle 5132 Mar 29 March 2012
Puzzle 5142 Mar 31 March 2012
Puzzle 5147 Apr 1 April 2012
Puzzle 5157 Apr 3 April 2012
Puzzle 5167 Apr 5 April 2012
Puzzle 5172 Apr 6 April 2012
Puzzle 5177 Apr 7 April 2012
Puzzle 5187 Apr 9 April 2012
Daily Killer Sudoku