Gimbun, J., N. F. Ishak, N. I. S. Muhammad, S. F. Pang, M. A. A. Kadir, H. Ramli, M. F. Abdullah, Z. Giman, and Z. Khadisah. “Ultrasonic Assisted Extraction Polyphenols AndD Antioxidant from Nigella Sativa Seed”. Journal of Engineering and Technology (JET), vol. 5, no. 2, Dec. 2014, pp. 17-26, https://jet.utem.edu.my/jet/article/view/157.