Hakk, E.A., A. Nada, A.N. Tawfik, and H. Yassin. “Impacts of Viscous Matter and Radiation on the Temporal Evolution of the Universe”. Ukrainian Journal of Physics 67, no. 6 (October 27, 2022): 448. Accessed April 26, 2024. https://ujp.bitp.kiev.ua/index.php/ujp/article/view/2021002.