Prastyo, E., R. B. Cahyono, L. Marbelia, and W. Budhijanto. “Comparative Study of the Single and Double-Stage Thermochemical Pretreatment of Gracilaria Sp. For Biogas Feedstock”. Journal of Engineering and Technological Sciences, vol. 58, no. 1, Dec. 2025, pp. 71-85, doi:10.5614/j.eng.technol.sci.2026.58.1.6.