Using of Third and Fourth Order Derivative Spectra to Simultaneous Determination of Olanzapine and Ephedrine in Its Pure and Pharmaceutical Formulations. IHJPAS [Internet]. 2017 Jun. 11 [cited 2024 May 5];30(1):366-75. Available from: https://jih.uobaghdad.edu.iq/index.php/j/article/view/1085