Qasem, M., محمد, Al-Hamadani, enam and انعام 2007. Citric acid production by different local isolates of mushrooms Aspergillus niger. Journal of Education and Science (JES). 20, 1 (Sep. 2007), 402–409. DOI:https://doi.org/10.33899/edusj.2007.162820.