This book will help you defend better regardless of your experience or skill level.
It explains several ways to describe your holding which are commonly  used by experts but not generally known. It compares new methods with  old, including the pros and cons of upside-down versus standard  signaling. It explains how to draw inferences, not only from partner's  signals, but also from what he fails to do.
Even if you are an expert and think there is nothing about defensive  signals you don't already know, you will probably see a few situations  you haven't thought about and discover how other experts handle them.
Originally published in 1995, this book has been unavailable for more than 20 years.