Heydarbeygi, Z., M. Amyari, and M. Khanehgir. “Some Refinements of Numerical Radius Inequalities”. Ukrains’kyi Matematychnyi Zhurnal 72, no. 10 (October 25, 2020): 1443 - 1451. Accessed March 29, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/6027.