RT Journal Article SR Electronic T1 Contractor Tree Trimming Crew Evaluations JF Arboriculture & Urban Forestry (AUF) FD International Society of Arboriculture SP 37 OP 39 DO 10.48044/jauf.1977.011 VO 3 IS 2 A1 Charles H. Miller YR 1977 UL http://auf.isa-arbor.com/content/3/2/37.abstract