RT Journal Article SR Electronic T1 Understanding racial-ethnic and societal differentials in STI JF Sexually Transmitted Infections JO Sex Transm Infect FD BMJ Publishing Group Ltd SP 2 OP 4 DO 10.1136/sti.78.1.2 VO 78 IS 1 A1 S O Aral YR 2002 UL http://sti.bmj.com/content/78/1/2.1.abstract AB