POPOWSKA, Marta. Jan Olbracht Gradual from the Archives of the Wawel Cathedral. Physical description. Edukacja Muzyczna, [S. l.], v. 13, p. 183–207, 2019. DOI: 10.16926/em.2018.13.11. Disponível em: https://czasopisma.ujd.edu.pl/index.php/EM/article/view/829. Acesso em: 3 maj. 2024.