The expert source for the opinions in the estimate is those of the owner, Mr. Apollo O’Neil. He is an ISA Certified Arborist, a certificate kept current by continuing education courses. ISA (International Society of Arboriculture) is the internationally recognized credentialing organization, headquartered in Champaign, Illinois. If you provide us with a fax number, he can fax you his certificates and licenses. You can also go to the official ISA website at www.isa-arbor.comto learn more about the organization and its activities. Just click on the “Enter the ISA website” tab. For certification confirmation, click on the third top green tab “Certification”, then click on the left column “Verify an ISA Certification”, then simplest is to click on “By Name” (it takes a little while to process) and then type in the exact spelling with apostrophe; O’Neil (this takes a little time to process) and then scan down to O’Neil, Apollo. You can also search by his Certification ID which is FL-6102A.