@misc{_Geologische_1929,
 copyright={Copyright by Uniwersytet Wrocławski},
 copyright={University of Wroclaw},
 howpublished={online},
 year={1929},
 publisher={Topogr. Aufnahme des Kgl. Preuss. Generalstabes},
 title={Geologische Karte 1:25 000 - 3011 Ruhbank},
 keywords={mapa geologiczna},
}