RT Journal Article SR Electronic T1 Abstract JF Arboriculture & Urban Forestry (AUF) FD International Society of Arboriculture SP 20 OP 20 DO 10.48044/joa.1987.13.1.20 VO 13 IS 1 YR 1987 UL http://auf.isa-arbor.com/content/13/1/20.abstract AB