Ptolemy,  Pirckheimer, Willibald,  Regiomontanus, Joannes,  and Grüninger, Johann, d. 1532?.  "Tabula X Europae."  Map.  1525.  Norman B. Leventhal Map & Education Center,  https://collections.leventhalmap.org/search/commonwealth:st74cz215 (accessed October 24, 2020).