Mora, J., B. Punthmatharith, and P. Wattanasit. “Effect of Positioning on Gastric Residual Volume in Preterm Infants”. Journal of Research in Nursing-Midwifery and Health Sciences, vol. 37, no. 4, Dec. 2017, pp. 35-46, https://he02.tci-thaijo.org/index.php/nur-psu/article/view/107742.