@misc{_Historya,
 howpublished={online},
 publisher={Polska Akademia Umiejętności, Kraków},
 publisher={Gebethner i Wolff},
 language={Polish},
 title={Historya polityczna Polski. Cz. 1, Wieki średnie},
 type={book},
 keywords={Poland, political history, Middle Ages},
}