100 Headachingly Hard Mate in Two Chess Puzzles Composed by Sam Loyd: Improve Your Ability to Calculate Variations and Finding Checkmate - Kindle edition by Justesen, Martin B.. Humor & Entertainment Kindle
Unbelievably hard puzzle! (rating 3000+, white to move)! - Chess Forums - Chess.com
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Hard Chess Puzzles
Hebden Bridge Chess Club: The Hardest chess problem in the world?
Hard Chess Puzzles
Hardest Chess Puzzle : [Checkmate in 1 move] Do you know all chess rules ? ( Board: Lichess ) - YouTube
5 Hardest Mate-in-2 Ever - TheChessWorld
An Ancient Chess Puzzle That Engines CAN'T Solve! - Remote Chess Academy