nusyirwan, nusyirwan, and Hayatul Fikri. “Study on the Flexural Strength of Polyester Composite Beams and Coconut Husk Charcoal Powder”. Jurnal Teknik Mesin (Journal Of Mechanical Engineering) 15, no. 01 (January 28, 2026): 83–89. Accessed June 3, 2026. https://publikasi.mercubuana.ac.id/index.php/jtm/article/view/23591.