S. Hartuti, Leotrido Pahalatua Nababan, Hanggara Sudrajat, and Nurmeizon Saleh, “Feasibility Study of TiO2-Coal Fly Ash Photocatalysts for Simultaneous Organic Pollutant Removal and Hydrogen Evolution from Greywater”, dampak, vol. 23, no. 2, pp. 88–103, Aug. 2026.