Bridge Bidding

"Bridge Bidding" is a free book written for Contract Bridge players whose ability ranges from advanced beginners to advanced.  It is not intended for experts.  The book is freely redistributable under an open-source license.
Bridge Bidding can be used as a reference book or for initial learning, but professional books have more examples and quizzes. Unlike nearly all bridge books, this book has an index and a glossary as well as the Table of Contents.
The book as a web site is at:  https://pfdubois.github.io/BridgeBidding/index.html

The copyright page has links to also get the book as a PDF, as a file for your e-book reader or tablet, as a download for offline use, and as a collection of individual text files for each chapter for easily sharing a topic with a partner.