RT Journal Article SR Electronic T1 Why Charge a Fee? JF Arboriculture & Urban Forestry (AUF) JO JOA FD International Society of Arboriculture SP 228 OP 229 DO 10.48044/jauf.1977.059 VO 3 IS 12 A1 Kenneth D. Meyer YR 1977 UL http://auf.isa-arbor.com/content/3/12/228.abstract