![Image](http://sbtree.com/wp-content/uploads/2017/12/Butterfly.jpg)
• National Arbor Day Foundation
• Oak Tree Preservation
• International Society of Arboriculture--consumer links--or--ISA home page
• Alex Shigo's books on trees and pruning
• National Arbor Day Foundation
• Oak Tree Preservation
• International Society of Arboriculture--consumer links--or--ISA home page
• Alex Shigo's books on trees and pruning