van Zyl, P. G.; Beukes, J. P.; du Toit, G.; Mabaso, D.; Hendriks, J.; Vakkari, V.; Tiitta, P.; Pienaar, J. J.; Kulmala, M.; Laakso, L. Assessment of Atmospheric Trace Metals in the Western Bushveld Igneous Complex, South Africa. S. Afr. J. Sci. 2014, 110 (3/4), 1-11. https://doi.org/10.1590/sajs.2014/20130280.