Auewarakul, Prasert. “Virulence of the H1N1 2009 Pandemic Influenza Virus”. Siriraj Medical Journal 63, no. 2 (April 3, 2020): 60–63. accessed October 4, 2026. https://he02.tci-thaijo.org/index.php/sirirajmedj/article/view/240909.