LAYCOCK, J. Beyond the Threshold of Hearing. Contact: A Journal for Contemporary Music (1971-1990), [S. l.], n. 2, 1971. DOI: 10.25602/GOLD.cj.v0i2.850. Disponível em: https://journals.gold.ac.uk/index.php/contactjournal/article/view/contactjournal02_p9-13. Acesso em: 4 may. 2024.