Killer Sudoku - Sudoku Puzzles Game for Android - Download

Killer Sudoku Puzzles by Krazydad

Extreme difficulty (maybe unsolvable?) killer sudoku : r/sudoku

Killer Sudoku Sarah Rubin Books

Insane Killer Sudoku

Hard Killer Sudoku - 100 Challenging by Hammond, Oliver

Puzzle#102: Killer Sudoku 6x6

Interactive Killer Sudoku by KrazyDad

Killer Sudoku Hard To Extreme Puzzles - By Senor Sudoku (paperback) : Target

Killer Sudoku by Sudoku.com on the App Store

Killer Samurai Sudoku