chankunasuka, rungfah, R. Chintanawat, and P. Juntasopeepan. “Relationship Between Anxiety of COVID-19 and Sleep Quality of Older Persons”. NU Journal of Nursing and Health Sciences, vol. 19, no. 3, Dec. 2025, pp. 116-31, https://he01.tci-thaijo.org/index.php/NurseNu/article/view/272389.