Keeping volunteers in service.
D000488:Allied Health Personnel / Q000600:supply & distribution*; D004634:Emergency Medical Technicians / Q000600:supply & distribution*; D006801:Humans; D009042:Motivation; D010559:Personnel Management / Q000379:methods*; D012201:Reward; D012424:Rural Population; D014481:United States; D014838:Volunteers / Q000600:supply & distribution*