<a href="//commons.wikimedia.org/wiki/Nicolaus_Copernicus" title="Nicolaus Copernicus">Nicolaus Copernicus</a>' letter in German to Duke Albrecht of Prussia, as taken from <a href="https://en.wikipedia.org/wiki/Leopold_Prowe" class="extiw" title="w:Leopold Prowe">w:Leopold Prowe</a>'s (1821-1887) <i>Nicolaus Coppernicus</i>, 1884. In Dvju-format for use in Wikisource <a href="//commons.wikimedia.org/w/index.php?title=File:Copernicus-an-Herzog-Albrecht.djvu&amp;action=edit&amp;redlink=1" class="new" title="File:Copernicus-an-Herzog-Albrecht.djvu (page does not exist)">File:Copernicus-an-Herzog-Albrecht.djvu</a>
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Nicolaus Copernicus</div>
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