RT Journal Article SR Electronic T1 CONTRIBUTED ABSTRACT JF Arboriculture & Urban Forestry (AUF) JO JOA FD International Society of Arboriculture SP 90 OP 90 DO 10.48044/joa.1979.5.4.90 VO 5 IS 4 YR 1979 UL http://auf.isa-arbor.com/content/5/4/90.abstract