I have read a few books on introversion, this one is the best by a long shot.
The book is short but don't let that put you off. It is full of relatable examples and some good insights. The text is up lifting and confidence inspiring. The cover of this book in itself is inspiring, I have purchased other books on this subject and the covers for the most part are dull and some depressing.
If your interested in this subject and want to feel good about yourself buy this book.