Rukmananda, Raditya, Sasana Putra, and Muhammad Karami. “Kualitas Bahan Bitumen Akibat Penambahan Kadar Lignin Yang Berbeda”. Jurnal Rekayasa Sipil dan Desain (JRSDD) 6, no. 4 (December 23, 2018): Hal. 433 – 444. Accessed December 10, 2025. http://journal.eng.unila.ac.id/index.php/jrsdd/article/view/1010.