Talib Al- Helaly, Mushaq. “Study the Physical Properties for Nitrogen Molecules by Using Software Molecular Modeling by using(PM3) Semiemperical Method of Quantum Mechanic”. Journal of Kufa-Physics, vol. 8, no. 1, June 2016, https://journal.uokufa.edu.iq/index.php/jkp/article/view/7468.