KROHM, H.J. 10 Years of photo-chemical smog monitoring in Johannesburg. Clean Air Journal, [S. l.], v. 8, n. 7, 1993. DOI: 10.17159/caj/1993/8/7.7311. Disponível em: https://cleanairjournal.org.za/article/view/7311. Acesso em: 31 may. 2025.