M. Almousawi, I., H. Mathkor, T., A. Salih, A., H. Afaj, A., & A.A.Shanshal, M. (2018). Statistical analysis of polycyclic aromatic hydrocarbons concentrations at Baghdad city. Al-Qadisiyah Journal of Pure Science, 23(1), 122 - 138. https://doi.org/10.29350/jops.2018.23.1.725