@misc{_M_[1939],
 copyright={Public Domain},
 address={Gotha},
 journal={Vogels Karte von Mitteleuropa. Fliegerkarte},
 howpublished={online},
 year={[1939]},
 publisher={Justus Perthes},
 language={ger},
 title={M 34-NW Krakau},
 type={Image},
 URL={http://rcin.org.pl/Content/210107/PDF/WA51_190996_PTGC61-16-r1939_M-34-NW-Krakau_0001.pdf},
 keywords={topographic maps, military maps, Upper Silesia, Kalisz region, Łódź region, Cracow region},
}