title: A circulation theory of needle exchange.
authors.forename: E H
authors.initials: EH
authors.lastname: Kaplan
authors.forename: R
authors.initials: R
authors.lastname: Heimer
mesh_terms: D003237:Connecticut; D003617:Dangerous Behavior; D004866:Equipment Contamination; D015658:HIV Infections / Q000517:prevention & control / Q000635:transmission; D006801:Humans; D008962:Models, Theoretical; D016485:Needle Sharing / Q000706:statistics & numerical data; D009339:Needles / Q000600:supply & distribution; D015397:Program Evaluation; D015819:Substance Abuse, Intravenous / Q000150:complications / Q000453:epidemiology