Book recommendations

[Jon Lad]

I wondered what books people have read, related to our industry, that they would definitely recommend to others. 
In terms of how informative; educational; interesting; funny or just helpful that they were. 
For myself, I would recommend any of these four  

[Doug Tait]

Liked the Fundamentals... by Beranek too, was very helpful when I knew nothing about climbing.

Also Claus Mattheck, The Body Language of Trees, Tree Mechanics, and Stupsi Explains the Tree.

Not sure it counts but the Valtra operators manual can be an interesting read at lunchtime if I'm out on my own with no internet reception.

[JSN]

The book that made it all make sense and one that I consistently recommend is Trees: Their Natural History by Peter Thomas. 

[Brushcutter]

ISA arborist's certification study guide. I only have the 3rd edition and the 4th is just out but is a must have for any bookshelf.