Stafilov, T., Z. Kovacevski, and M. Trajkovska. “Determination of Lead in Air by Electrothermal Atomic Absorption Spectrometry”. Macedonian Journal of Ecology and Environment, vol. 1, no. 1-2, Dec. 1993, pp. 88-96, https://mjee.org.mk/index.php/mjee/article/view/139.