Jim McKeown's books are the most comprehensive sources of accurate information on cameras in the world. Period. Other books may give more information on specific cameras, but if you are to have but one source to refer to,choose McKeown. He will never disappoint you.
Another wonderful camera expert and writer (they don't always go together) is Ivor Matanle. His two books are treasures. But if you want facts, go with McKeown. You will return over and over to his book. Speaking face to face with him is most rewarding. You realize you are learning from one of the world authorities.
Wonderful pictures, camera values (prices) rarity,etc. This book contains cameras even experts haven't heard about. But McKeown is the expert of experts, and you will keep this large,heavy, over 900 page book near just for the fun of reading it. Am I enthused? Yes! I have bought his books since the 4th edition in 1983-84, and always been pleased.
A lengthy review? Yes, but this book deserves much praise!