Ahmad Nordin, Norain, Khairunnisa Muhammad, Mashitah Mohamed Noor, and Manizira K. Leny Annan. 2021. “Effect of Piper Betle Extract Hand Sanitizer in Reducing Microbes on Hands by Using Fingertips Touch Plate Method”. Multidisciplinary Applied Research and Innovation 2 (2): 226–233. https://publisher.uthm.edu.my/periodicals/index.php/mari/article/view/2014.