@misc{Janusz_Ziółkowski_Upper_1957,
 author={Janusz Ziółkowski},
 address={Poznań},
 year={1957},
 contents={Strona 13-14},
 publisher={Poznań : IZ,},
 language={pol},
 title={Upper iSilesia Industrial District and its Economic and Geogra- phic Problems},
 type={text},
}