The Complete Master Key System by Charles F Haanel is a mental health book that was originally written in 1912 by the author. This paperback edition, published in 2010, includes 28 additional chapters and is 252 pages long. Written in English, the book explores techniques for achieving mental clarity and success, making it a valuable resource for those looking to improve their mental well-being. At 229mm in height and 152mm in width, this book is a practical and informative read for anyone interested in personal development. Apparently the young Bill Gates read it before starting Microsoft.