With one exception this is hands down the best book available on the German Leopard I Main Battle Tank. The exception is that all of the text is in French.
Back in about 1970 the Germans and the Americans decided to work together to build a new tank that was going to be the absolute state of the art. The resulting tank the MBT 70 wasn't liked by anybody. It was too heavy, too expensive, too everything. So the partnership split apart with the Americans proceeding to design the Abrams M1 and the Germans the Leopard I. I believe that both of these tanks were heavier and more expensive than the MBT 70, but that's another story.
This book is the story of the Leopard I, from its design to actual use. It covers the various models that were built to come up with the final design, the optional features that various countries have used, and finally a summary of all of the countries that have used the tank.
The book is beautifully printed, with probably a couple of hundred color photographs. I wish I read French better than I do. I must say that the book I have has a different front cover than the one pictured at Amazon, but it has the same ISBN.