Logic Wiz: Squares Sudoku. Jigsaw(irregular), Reflection, Arrow & Thermo Sudoku. Rules and links in the first comment. : r/sudoku
Tough Killer Sudoku, Volume 2, Book 11 - KrazyDad
Killer Sudoku and His Friends: Killer sudoku and Kin-kon-kan hard - extreme levels. : Sudoku puzzles book to the road. (Series #8) (Paperback) - Walmart.com