Maneewong, J., K. panthu, and R. Phorang. “The Correlation betweenPain Perception and Pain Management in elderly patients undergoing surgery at aTertiaryLevel Hospital”. Journal of Nursing, Siam University, vol. 21, no. 41, Jan. 2021, pp. 29-40, doi:10.14456/jnsu.v21i41.243306.