Chess Database - Opening Master

Best Chess Openings for White & Black (42 Openings)

Best Chess Openings for White: Full Guide - 365Chess

How to Win at Chess Openings - Complete Guide - TheChessWorld

Chess Opening Database - Chess Forums

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

We made a tool that lets you search the lichess game database by chess concepts. Link in the comments : r/chess

Physics - Power laws in chess

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

Chess Openings Pro - Apps on Google Play

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