@misc{_M_[1944], copyright={Public Domain}, address={Gotha}, journal={Vogels Karte von Mitteleuropa. Fliegerkarte}, howpublished={online}, year={[1944]}, publisher={Justus Perthes}, language={ger}, title={M 33 - SO Wien}, type={Image}, URL={http://www.rcin.org.pl/Content/210178/PDF/WA51_191529_PTGC61-19-r1944_M-33-SO-Wien_0001.pdf}, }