Mohammed, M. M., H. Radhi, M. A., & Nasir, A. Y. (2009). Studying the Factors Effect on the Flowability of (ZnO – CuO/ Al2O3) Catalyst with Blending of Different Lubricants through Hopper. Al-Khwarizmi Engineering Journal, 5(4), 18-24. https://alkej.uobaghdad.edu.iq/index.php/alkej/article/view/579