@misc{Ostwald_Paul_Der,
 author={Ostwald, Paul},
 howpublished={online},
 publisher={Velhagen & Klasing},
 language={ger},
 title={Der Deutsche Ritterorden : Urkunden, Chroniken, Darstellungen},
 type={książka},
 keywords={Prusy - historia, Zakon Krzyżacki - historia},
}