Sawattikanon, N., K. Uttrarachon, R. Pongvuthithum, T. Sucharitakul, and W. Rangsri. “A Prototype of Automatic Mattress Turning Device for Pressure Ulcer Prevention”. Journal of Associated Medical Sciences, vol. 52, no. 1, Dec. 2018, pp. 89-92, https://he01.tci-thaijo.org/index.php/bulletinAMS/article/view/119291.