@misc{Ptak_Barbara_(1930-_)_Bal,
 author={Ptak, Barbara (1930- )},
 address={Katowice},
 howpublished={online},
 publisher={Wydawnictwo Artystyczno-Graficzne},
 publisher={RSW "Prasa"},
 language={pol},
 type={plakat},
 title={Bal w operze : R. Heuberger},
}