URSPRUNG, Otto. Das Freisinger Petrus-Lied. Die Musikforschung, [S. l.], v. 5, n. 1, p. 17–21, 2021. DOI: 10.52412/mf.1952.H1.2780. Disponível em: https://mf.journals.qucosa.de/mf/article/view/2780. Acesso em: 27 nov. 2024.