@misc{Kopernik_Mikołaj_(1473-1543)_[List,
 author={Kopernik, Mikołaj (1473-1543)},
 address={Ritzingen/Main},
 howpublished={online},
 publisher={Holzner Verlag},
 language={ger},
 type={list},
 title={[List do Albrechta, księcia pruskiego. Frombork 21 VI 1541]},
}