BREIG, Werner. Udo Bermbach: Der anthroposophe Wagner. Rudolf Steiner über Richard Wagner. Die Musikforschung, [S. l.], v. 76, n. 4, p. 449–450, 2025. DOI: 10.52412/mf.2023.H4.4303. Disponível em: https://mf.journals.qucosa.de/mf/article/view/4303. Acesso em: 23 feb. 2025.