@misc{_Plan_[ca,
 copyright={Public Domain},
 address={Berlin (Potsdamer Strasse 129/130)},
 howpublished={online},
 year={[ca 1920]},
 publisher={Deutsche Nafta-Gesellschaft},
 language={ger},
 title={Plan der Nafta-Felder in Tustanowice (Galizien)},
 keywords={economic maps, oil fields, Tustanowice, Polska, 20th century},
}