@misc{_Polska_[ca,
 copyright={Public Domain},
 address={[S.l.]},
 howpublished={online},
 year={[ca 1800]},
 publisher={[s.n.]},
 language={pol},
 title={Polska za Mieczyslawa I},
 type={Image},
 keywords={historical maps, Poland, 10th century},
}