Mohammed, A. K., S. B. Dikran, and M. Abdul Sattar Alubydi. 2016. “Univariate and Simplex Optimization for The Analysis of Diphenhydramine-HCl Through Ion-Pair Formation”. Ibn AL-Haitham Journal For Pure and Applied Sciences 24 (1). https://jih.uobaghdad.edu.iq/index.php/j/article/view/864.