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
Difficult puzzle. White to play, mate in 2. : r/chess
Hardest Checkmate in Two Puzzle??? 7# - YouTube
Checkmate in Two Puzzles Test (Very Hard) - Chess.com
Hard Chess Puzzles – Solve Most Difficult Chess Puzzles
Hardest Checkmate in 1 - Chess Forums - Chess.com
Hard Chess Puzzles
Difficult Chess Puzzles for Advanced Players
G. T. Karber on Twitter: "I love this chess puzzle that Paul Morphy composed when he was 10. See if you can find mate in 2 for white. https://t.co/4Kg1qoVe0K" / Twitter
A really hard but amazing endgame puzzle. White to move and win. : r/chess
What are some of the toughest chess puzzles? - Quora