D. C. Birawidha, K. Isnugroho, Y. Hendronursito, M. Amin, and M. Al Muttaqii, “STUDY OF MAKING POLYESTER RESIN MATRIX COMPOSITES USING BASALT SCORIA POWDER FILLERS TO TENSILE STRENGTH AND COMPRESSIVE STRENGTH”, Sinergi, vol. 25, no. 3, pp. 299–308, Aug. 2021.