Thuchart, S., U. Asdornwised, W. Pinyopasakul, and A. Trakarnsanga. “The Effects of Concrete-Objective Information Program on Pre-Operative Anxiety in Abdominal Surgery Patients”. Nursing Science Journal of Thailand, vol. 37, no. 2, May 2019, pp. 78-91, https://he02.tci-thaijo.org/index.php/ns/article/view/192756.