Chawanpaiboon, S. ., P. . Wanitpongpan, V. Titapant, S. . Kanokpongsakdi, C. . Wantanasiri, K. . Pimol, and R. . Sirisomboon. “Nifedipine for Inhibiting Threatened Preterm Labour in Siriraj Hospital”. Siriraj Medical Journal, vol. 60, no. 3, May 2008, pp. 111-3, https://he02.tci-thaijo.org/index.php/sirirajmedj/article/view/246366.