“Hermite-Hadamard Type Integral Inequalities for Functions Whose Mixed Partial Derivatives Are Co-ordinated Preinvex” (2025) Punjab University Journal of Mathematics, 52(1), pp. 63–76. Available at: https://pujm.pu.edu.pk/index.php/pujm/article/view/313 (Accessed: 29 June 2025).