N. F. N. Yah, H. A. Rahim, Y. S. Lee, F. H. Wee, and H. H. Zainal, “Electromagnetic Wave Absorption Properties of Novel Green Composites Coconut Fiber Coir and Charcoal Powder over X-band Frequency for Electromagnetic Wave Absorbing Applications”, AEM, vol. 7, no. 1, pp. 13–18, Jan. 2018.