The Ideal soil 2.0, can be found free online. Or You can try and find Carey Reams and W Albrecht's lectures.
A go to soil source, straight forward easy advice. Helps create independence from agronomists.
One straw revolution, M. Fukuoka
Back to nature, M. Fukuoka
I've saved lot's of money by following some of Fukuoka's advice.
A Botany book that is used in university. They are expensive but will knock any garden book to the ditch since it got proper science so you know your getting the basics right, Like how soil is formed, photosyn, hydrolysis, phyllotaxis. This will help you save a lot of money since you will be able to avoid snake oil products or bad advice from others.
The Bible have some good sections but you got to know where to look.
I did read Bill whitmans book, 40 years with tropical fruit.
A lot of the book is full of rare fruit council meeting minutes and letters and such, so Isn't really a book IMO, more like a collection of articles. I think those articles can be found online for free too in a rare fruit archive.
Peace