Fawz Abdul Salam K.AL-Saffar, Abdul Razak K. Mahmood, and Najwa I. AL- Barhawi, “Investigation at the molecular level for a nifgenes to bacteria klebsiella pneumoniea the use of polymerase chain reaction (PCR)”, Tikrit J. Pure Sci., vol. 22, no. 3, pp. 58–62, Jan. 2023.