nusyirwan nusyirwan, Fikri H. Study on the Flexural Strength of Polyester Composite Beams and Coconut Husk Charcoal Powder. JTM [Internet]. 2026 Jan. 28 [cited 2026 Jun. 3];15(01):83-9. Available from: https://publikasi.mercubuana.ac.id/index.php/jtm/article/view/23591