Sutthichon , P. ., and K. Jearwattanakanok. “Treatment Success and Associated Factors in Unknown Stage Syphilis Treated With Standard Regimen in Nakornping Hospital”. Journal of Nakornping Hospital, vol. 11, no. 2, Nov. 2020, https://he01.tci-thaijo.org/index.php/jnkp/article/view/245233.