WALKER, N.P.; ELLERBECK, R.H. A COMPARISON BETWEEN SOILING INDEX AND TOTAL CARBON CONCENTRATIONS. Clean Air Journal, [S. l.], v. 7, n. 1, p. 30–31, 1986. DOI: 10.17159/caj/1986/7/1.7347. Disponível em: https://cleanairjournal.org.za/article/view/7347. Acesso em: 20 jun. 2024.