Ngamprasert, Malee, Orapan Thosingha, Pongsri Srimoragot, Suporn Danaidutsadeekul, Saipin Gasemgitvatana, and Soranit Siltharm. 2003. “Risk Factors of Pressure UIcers in Hospitalized Elderly”. Siriraj Medical Journal 55 (2):78-90. https://he02.tci-thaijo.org/index.php/sirirajmedj/article/view/245378.