Ren, Xiaomin. “Nitrogen-Phosphorus Co-Doped Graphene for Enhanced Flame Retardancy and Smoke Suppression in Asphalt”. International Core Journal of Engineering 11, no. 8 (August 4, 2025): 109–120. Accessed July 6, 2026. https://icj-e.org/index.php/ojs/article/view/99.