ABDALLA, Y. H.; MAJID, A. A.; ABDELNABY, O. H. The effect of nitrification inhibitors and sulfur on the efficiency of nitrogen fertilizers added to calcareous soil on barley plant in El-Jabal El Akhdar region. Al-Mukhtar Journal of Sciences, v. 31, n. 2, p. 55–64, 31 Dec.2016.