Vu และ Van Chieu. (2010) Factors affecting sexual risk behavior among injecting drug users in Vietnam. Mahidol University:ม.ป.ท.Vu และ Van Chieu. 2010. Factors affecting sexual risk behavior among injecting drug users in Vietnam. ม.ป.ท.:Mahidol University;Vu และ Van Chieu. Factors affecting sexual risk behavior among injecting drug users in Vietnam. ม.ป.ท.:Mahidol University, 2010. Print.