publication 1989 Prevalence and activity of some diazotrophs in Saudi Arabian soils Pages 321-334 more of publication الميكروبات في حياتنا 2009 Published in: مكتب التربية العربي لدول الخليج. Effect of organic amendment and/or salinity on nitrogenase activity of arid soils. by Barakah F. N, EL-Shahawy R. M. 1988 Prevalence and activity of some diazotrophs in Saudi Arabian soils by EL-Shahawy, R. M, Barakah F. N 1989