@misc{Ciesielski_Jan_The_1987,
 author={Ciesielski, Jan and Schwartz, Aleksander},
 copyright={Instytut Geodezji i Kartografii},
 address={Warszawa},
 howpublished={online},
 year={1987},
 publisher={Instytut Geodezji i Kartografii},
 language={eng},
 language={pol},
 language={ros},
 title={The hydrographic map of Poland at the scale 1:50 000},
 type={czasopismo},
 keywords={mapa hydrograficzna, Polska},
}