Kalaf, Salim.H., and Adal.M. Abdala. “The Impact of Critical Success Factors on Improving Employee Productivity Analytical Study in Al-Mishraq Sulfur Plant”. Tikrit Journal of Administrative and Economic Sciences, vol. 18, no. 58, 2, June 2022, pp. 215-34, doi:10.25130/tjaes.18.58.2.13.