SumSudoku: Killer Sudoku - Apps on Google Play

Killer Sudoku Puzzles by Krazydad

Killer Sudoku - Play Killer Sudoku online

Children's Killer Sudoku Magazine

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

About Killer Sudoku Puzzles

Killer / Thermo-Sudoku by Michael Rios - The Art of Puzzles

Killer sudoku (Question for experienced players) : r/sudoku

Killer Sudoku - Sudopedia

A Gorgeous Killer Sudoku Trick

Variety Puzzle Books for Adults - 400 Normal Puzzles 9x9: Killer Sudoku, Killer Sudoku X, Killer Sudoku Jigsaw, Argyle Killer Sudoku (Volume 16) (Paperback)