AUSTIN, Brian A. Radio communications through rock strata – South African mining experience over 50 years. South African Journal of Science, [S. l.], v. 120, n. 3/4, 2024. DOI: 10.17159/sajs.2024/17301. Disponível em: https://sajs.co.za/article/view/17301. Acesso em: 11 may. 2024.