ECO, Umberto. Hard and Soft Communication. Observatorio (OBS*), [S. l.], v. 15, n. 2, 2021. DOI: 10.15847/obsOBS15220212010. Disponível em: https://obs.obercom.pt/index.php/obs/article/view/2010. Acesso em: 25 apr. 2024.