http://forestry.about.com/od/insects/tp/An-Index-of-Common-Tree-Insect.htm

http://forestry.about.com/od/forestinsects/p/hwd_ins_worst.htm

http://forestry.about.com/od/foresthealth/a/tree_pest_ndex.htm

Proper Tree Pruning Practices

www.glpti.org/proceedings/2008/20_proper_tree_removal.pdf