State barriers to SEPs.
Makulowich
G S
GS
D003625:Data Collection; D015658:HIV Infections / Q000517:prevention & control*; D006801:Humans; D018671:Needle-Exchange Programs / Q000331:legislation & jurisprudence* / Q000592:standards / Q000706:statistics & numerical data*; D015397:Program Evaluation; D014481:United States