C. Gonzales, R. Megallos, I. P. Ignacio, and M. A. Cao, “Effects Of Coal, Wood, And Crop Ashes on the Compressive Strength and Water Absorption of Eco-Friendly Building Blocks”, IJERIP, vol. 2, no. 5, pp. 1689–1696, May 2026, doi: 10.5281/zenodo.20405367.