RT Journal Article SR Electronic T1 Local, state agencies using contact tracing to halt coronavirus spread: 100,000 more tracers needed across US JF The Nation's Health JO Nations Health FD American Public Health Association SP 1 OP 14 VO 50 IS 5 A1 Barna, Mark YR 2020 UL http://www.thenationshealth.org/content/50/5/1.2.abstract AB