“Role of Single and Mixed Culture of Pseudomonas Aeruginosa and Serratia Ficaria in Utilization of Petroleum Wastes of Dora- Refineries”. Baghdad Science Journal, vol. 4, no. 4, Dec. 2007, pp. 542-8, https://bsj.uobaghdad.edu.iq/index.php/BSJ/article/view/835.