Arif11, Ghassan E., Samer R. Yassen1, Abdulsameeh.F.Abdul Aziz2, & Summar.W. Omer1. " Constructing Mathematical Models to Find a Relationship between Physical Compounds Using the Graph Theory." Tikrit Journal of Pure Science [Online], 25.6 (2020): 126-129. Web. 1 Mar. 2021