That's a good question. I am not sure about any specific books that cover really diverse gardening methods... but I can share two books that really influenced my own thinking and style of gardening:

• Gaia's Garden by Toby Hemenway
• One Straw Revolution by Fukuoka Masanobu

Both books have led me down a path of letting go of my desire to control nature and control my garden. Ultimately I still exercise a lot of control, but now I allow more room for chaos.

I am definitely an advocate of perennial and polycultures because they can lend us to a more horticultural approach to gardening rather than an agricultural approach. I don't know a lot about historical methods and have only picked up bits here and there... I do agree that it would be interesting to learn more there!