RYAN, J.; CSERMAK, B. A low-noise directional microphone system. Canadian Acoustics, [S. l.], v. 32, n. 3, p. 70–71, 2004. Disponível em: https://jcaa.caa-aca.ca/index.php/jcaa/article/view/1632. Acesso em: 19 apr. 2024.