“Effect of Fibres Length on Acoustic Properties of Betel Nut Husk (Areca Nut Husk) Fibers–Reinforced Epoxy Composites”, JTM, vol. 9, no. 2, hlm. 46–51, Okt 2019, doi: 10.21063/jtm.2019.v9.i2.46-51.