@misc{Töppen_Max_(1822-1893)_Historisch-comparative,
 author={Töppen, Max (1822-1893)},
 address={Gotha},
 howpublished={online},
 publisher={Justus Perthes},
 language={ger},
 type={książka},
 title={Historisch-comparative Geographie von Preussen},
}