Towarek, Piotr. “Prayer „Sub Tuum praesidium”: Time of Origin, Place in Liturgy and Reception in Musical Culture. Outline of the Issues”. Vox Patrum 80 (December 15, 2021): 239–268. Accessed September 22, 2023. https://czasopisma.kul.pl/index.php/vp/article/view/12929.