“DETERMINATION OF SERUM TRACE ELEMENTSMAGNESIUM, COPPER, ZINC, AND SELENIUM IN ASTHMATIC PATIENTS BY ATOMIC ABSORPTION SPECTROPHOTOMETRY”. Al-Nahrain Journal of Science, vol. 13, no. 1, Mar. 2010, pp. 20-25, https://anjs.edu.iq/index.php/anjs/article/view/1135.