FICKER, Friedbert. Nikolaus Dankov and Cartography in Bulgaria. Zeitschrift für Balkanologie, [S. l.], v. 41, n. 1, 2005. Disponível em: https://zeitschrift-fuer-balkanologie.de/index.php/zfb/article/view/44. Acesso em: 16 oct. 2026.