RT Journal Article SR Electronic T1 Urban Tree Diseases and the Need for Arboricultural Medicine JF Arboriculture & Urban Forestry (AUF) JO JOA FD International Society of Arboriculture SP 198 OP 201 DO 10.48044/jauf.1978.050 VO 4 IS 9 A1 Erik Jorgensen YR 1978 UL http://auf.isa-arbor.com/content/4/9/198.abstract