@misc{_Grossblatt_[1940],
 copyright={Public Domain},
 journal={Karte des Deutschen Reiches 1:100 000},
 howpublished={online},
 year={[1940]},
 language={pol},
 language={ger},
 title={Grossblatt Nr 45, Johannsburg},
 type={Image},
 keywords={topographical maps, Pisz},
}