FEIG, G.; GARLAND, R. M.; NAIDOO, S.; MALULEKE, A.; VAN DER MERWE, M. Assessment of changes in concentrations of selected criteria pollutants in the Vaal and Highveld Priority Areas. Clean Air Journal, [S. l.], v. 29, n. 2, 2019. DOI: 10.17159/caj/2019/29/2.7464. Disponível em: https://cleanairjournal.org.za/article/view/7464. Acesso em: 9 dec. 2022.