@misc{Pierson_William_(1833-1899)_Preussische,
 author={Pierson, William (1833-1899)},
 howpublished={online},
 publisher={Berlin: Verlag von Gebrüder Paetel},
 language={pol},
 title={Preussische Geschichte, Bd. 1},
 type={książka},
 keywords={historia, Prusy},
}