Gassim, Tawassul Mahadi. “The Study of ( Columba Livia Domestica) Pigeon As Bioindicator of Contamination With Zinc, Lead and Cadmium in Khartoum State”. Journal of Faculty of Education 7 (October 5, 2021). Accessed April 4, 2025. http://onlinejournals.uofk.edu/index.php/JFE/article/view/373.