This book describes different styles and different bits for the control of horses. It describes the reasons for the differences and should help a horseman pick the most suitable.
Librarian note: There is more than one author in the Goodreads adatabase with this name This profile may contain books from multiple authors of this name
This book is a bit dated now; however, the straightforward style is helpful and I learned a few things. There are a lot of photographs to illustrate the author's point which is nice.