Mousa, Khalid M., Fouad A. A. Al-saady, and May E. Mahmood. “NICKEL RECOVERY FROM RESIDUE OF HEAVY OIL USING NITRIC ACID”. Journal of Petroleum Research and Studies 2, no. 2 (July 1, 2011): 87-96. Accessed December 21, 2024. https://jprs.gov.iq/index.php/jprs/article/view/43.