Author(s): DAILY TELEGRAPH

ATLAS & REFERENCE

Brace your braincells for a mental workout with this collection of killer sudoku from the Telegraph. Prepare yourself to take on the challenge that is Telegraph Killer Sudoku 1. The ultimate test of logic, these demanding puzzles will put your mind through its paces. 200 killer sudoku grids allow you to hone your puzzling skills on your commute, during your leisure time or whenever you have a spare minute!