Turabov Nurmukhammat, Todjiev Jamoliddi, Allanazarova Dilafruz. “SPECTROPHOTOMETRIC DETERMINATION OF ZINC(II) AND COPPER(II) IONS”. International Journal of Advanced Science and Technology, Vol. 29, no. 05, June 2020, pp. 12383-96, http://sersc.org/journals/index.php/IJAST/article/view/25836.