Ptolemy,  Grüninger, Johann, d. 1532?,  Pirckheimer, Willibald,  and Regiomontanus, Joannes.  "Tabula VI Asiae."  Map.  1525.  Norman B. Leventhal Map & Education Center,  https://collections.leventhalmap.org/search/commonwealth:9g54xj55w (accessed September 21, 2020).