RT Journal Article SR Electronic T1 Abstracts JF Arboriculture & Urban Forestry (AUF) JO JOA FD International Society of Arboriculture SP 20 OP 20 DO 10.48044/joa.1977.3.1.20 VO 3 IS 1 YR 1977 UL http://auf.isa-arbor.com/content/3/1/20.abstract AB