KELSALL, T.; FITZMAURICE, M. Quantifying public address system performance in a public transit environment. Canadian Acoustics, [S. l.], v. 30, n. 3, p. 40–41, 2002. Disponível em: https://jcaa.caa-aca.ca/index.php/jcaa/article/view/1444. Acesso em: 19 jan. 2022.