Zainudin, M. H. H., and K. A. Abdullah. “Petroleum Jelly As an Alternative Coupling Agent to Reduce Umbrella Artifacts in Ultrasound Superficial Scans”. Malaysian Journal of Medicine and Health Sciences, vol. 21, no. 4, July 2025, pp. 138-43, http://mjmhsojs.upm.edu.my/index.php/mjmhs/article/view/1273.