7Van den Hoek A, Fu Y, Nicole HT, et al. High prevalence of syphilis and other sexually transmitted diseases amc~ sex workers in China[J] .AIDS, 2001,15:753 - 759.
9GRAY RH,WSWER MJ, BROOKMEYER R, et al. Probability of HIV-1 transmission per coital act in monogam- ous. hererosexual,HIV-l-discordant couples in Rakai, Uganda [J]. Lancer,2001, 357: 1149-1153.