@misc{Leoncavallo_Ruggero_(1857-1919)_Poranek,
 author={Leoncavallo, Ruggero (1857-1919)},
 howpublished={online},
 publisher={Gebethner i Wolff},
 language={pol},
 type={druk muzyczny},
 title={Poranek},
 title={(Mattinata)},
}