Sanglab, J., T. Daramas, and C. Kongsaktrakul. “Effects of Expressed Breast Milk on Pain Response to Tracheal Suction in Premature Infants”. Nursing Research and Innovation Journal, vol. 22, no. 1, Aug. 2016, pp. 49-64, https://he02.tci-thaijo.org/index.php/RNJ/article/view/42730.