Anti Diagonal Sudoku Puzzle (Fun With Sudoku #389)
Pentomino-Diagonal Sudoku — Rätselportal — Logic Masters Deutschland
Anti-Diagonal-Sudoku Ser.: Anti-Diagonal-Sudoku 16x16 - Leicht Bis Extrem Schwer - Band 2 - 276 Rätsel by Nick Snels (2015, Trade Paperback) for sale online | eBay