RT Journal Article SR Electronic T1 Abstracts JF Arboriculture & Urban Forestry (AUF) JO JOA FD International Society of Arboriculture SP 218 OP 218 DO 10.48044/joa.1989.15.9.218 VO 15 IS 9 YR 1989 UL http://auf.isa-arbor.com/content/15/9/218.abstract