Suntharasaj , T., R. Leetanaporn, S. Promsalee, and V. Chandeying. “Indicators of AIDS Prevention Among Vocational Students in Songkhla”. Thai Journal of Obstetrics and Gynaecology, vol. 6, no. 2, July 1994, pp. 107-16, https://he02.tci-thaijo.org/index.php/tjog/article/view/257780.