“Effect of Copper Sulfate Impregnation on the Physical-Mechanical Properties of Sengon and Coconut Wood: Pengaruh Impregnasi Tembaga Sulfat terhadap Sifat Fisis-Mekanis Kayu Sengon dan Kelapa”, perennial, vol. 22, no. 2, pp. 93–100, Oct. 2026, doi: 10.24259/perennial.v22i2.53690.