Rauf, Nawzad Khalid. “History Petroleum and Bitumen and Their Uses by Muslims in The Abbasid Age (132-656 AH 749-1258 AD)”. Journal of University of Raparin 8, no. 4 (December 28, 2021): 542–571. Accessed May 7, 2024. https://journal.uor.edu.krd/index.php/JUR/article/view/676.