Long-term trends in smoke and sulphur dioxide pollution in South Africa. Clean Air Journal, [S. l.], v. 6, n. 4, 1983. DOI: 10.17159/caj/1983/6/4.7264. Disponível em: https://cleanairjournal.org.za/article/view/7264. Acesso em: 13 nov. 2024.