PIOTROWSKI, Bernard. Nordeuropa und die Ostblockstaaten (ca. 1965-1990). Folia Scandinavica Posnaniensia, [S. l.], v. 3, p. 23–30, 2007. Disponível em: https://pressto.amu.edu.pl/index.php/fsp/article/view/10885. Acesso em: 28 mar. 2024.