Chess Notes by Edward Winter

OpeningsTrainer/openings.php at master · clarkerubber/OpeningsTrainer · GitHub

Gambit Chess Opening, PDF, Chess Openings

Chess Opening Blunders, PDF, Chess Openings

The Project Gutenberg eBook of Chess Strategy, by Edward Lasker

Why are a number of openings named after countries in chess (board games, naming, and culture)? - Quora

Ruy López Opening: Berlin, Rio Gambit Accepted - Chess Openings

Chess Opening Basics: Berlin, Rio de Janeiro Variation - Chessable

What are this sub's thoughts on the Ruy Lopez: Rio de Janeiro Variation? : r/chess

Ruy Lopez Opening Nf6 Variation – Berlin Defence

Most Aggressive opening Rio GAMBIT ACCEPTED RUY LOPEZ attack with black pieces, Berlin defense