Ungkhara, G., and T. Athakris. “Efficacy of Sterile Water Compared with Normal Saline Solution for Nasal Irrigation on the Sinonasal Symptoms in Chronic Sinusitis Patients”. Vajira Medical Journal : Journal of Urban Medicine, vol. 52, no. 3, Sept. 2011, pp. 193-9, https://he02.tci-thaijo.org/index.php/VMED/article/view/360.