Ioannis K. Argyros, Yeol Je Cho, and Santhosh George. “Extending the Convexity of Nonlinear Image of a Ball Appearing in Optimization”. Contemporary Mathematics 1, no. 4 (August 20, 2020): 209–214. Accessed May 7, 2024. https://ojs.wiserpub.com/index.php/CM/article/view/405.