@misc{_N_[1944],
 copyright={Public Domain},
 address={Gotha},
 journal={Vogels Karte von Mitteleuropa. Fliegerkarte},
 howpublished={online},
 year={[1944]},
 publisher={Justus Perthes},
 language={ger},
 type={Image},
 title={N 33 - SO Posen},
 URL={http://www.rcin.org.pl/igipz/Content/210102/PDF/WA51_190872_PTGC61-9-r1944_N-33-SO-Posen_0001.pdf},
 keywords={topographic maps, aerial maps, Wielkopolska, Pomeranian Lakeland},
}