FOURIE, O.L.; VENTER, J.C. ANALITIESE ONDERSOEK VAN BRIGGS-PLUIMSTYGING. Clean Air Journal, [S. l.], v. 6, n. 2, p. 9–16, 1982. DOI: 10.17159/caj/1982/6/2.7373. Disponível em: https://cleanairjournal.org.za/article/view/7373. Acesso em: 19 may. 2024.