- Arizona Landscape Contractors’ Association
www.alca.org - International Society of Arboriculture
isa-arbor.org - Arizona Community Tree Council, Inc
aztres.org - Arizona Nursery Association
www.azna.org - Boyce Thompson Arboretum
www.ag.arizona.edu/bta/ - Trees Are Good
www.treesaregood.com - Desert Botanical Garden
www.dbg.org - Pest Management Division (PMD)
www.sb.state.az.us - Maricopa Country Cooperative Extension publications search
www.extension.arizona.edu/pubs - ASU Library of Arizona Landscape Plants www.public.asu.edu