@misc{Ferra_Bertomeu_Chopin,
 author={Ferra, Bertomeu},
 howpublished={online},
 publisher={[b. m.]},
 language={eng},
 title={Chopin and Georg Sand in the Cartuja de Valldemosa},
 type={książka},
 keywords={Chopin, Fryderyk (1810-1849), George, Sand},
}