K. Al-Dawery, Salam, Zuhair A-A. Khammas, and Thaer Adnan Abdulla. 2009. “Purification of Zinc Oxide Using Direct Thermal Process by Petroleum Coke”. Iraqi Journal of Chemical and Petroleum Engineering 10 (1): 35-41. https://doi.org/10.31699/IJCPE.2009.1.6.