RT Journal Article SR Electronic T1 Abstract JF Arboriculture & Urban Forestry (AUF) FD International Society of Arboriculture SP 223 OP 223 DO 10.48044/joa.1981.7.8.223 VO 7 IS 8 YR 1981 UL http://auf.isa-arbor.com/content/7/8/223.abstract AB