Ahmed A. K. Al-Zubaidi, et al. “Estimation of Laed , Cadmium and Mercury Metals in the Blood Serum of Workers in the Coal Manufacture and Their Effects on Some Biochemical Parameters”. Tikrit Journal of Pure Science, vol. 21, no. 2, Feb. 2023, pp. 80-84, doi:10.25130/tjps.v21i2.975.