Modern Chess Openings. Kings Indian Defence

Best Chess Openings for White & Black (42 Openings)

learning - Where can I find free training tools like detailed annotated chess openings, middle games and endgames in the PGN format? - Chess Stack Exchange

Does the win/draw/loss rate from the opening database also apply to lower rated games? - Chess Forums

How to use a Chess Database to Improve your Openings

We made a website to study chess openings : r/chess

ChessBase opening tree statistics

Study Chess Openings like a Pro! - Alberto Chueca - High Performance Chess Academy

Small Encyclopedia of Chess Openings ABCDE on CD (3rd Edition)

Use Chessify Reference to Explore Chess Openings and Find Games

Chess Repertoire Explorer