@misc{Lévy_Maurice_(1838–1910)_Sur_1888,
 author={Lévy, Maurice (1838–1910)},
 copyright={Public Domain},
 address={Paris},
 howpublished={online},
 year={1888},
 publisher={Gauthier-Villars et Fils},
 language={fre},
 language={fre},
 type={Text},
 title={Sur le principe de l'énergie},
 URL={http://www.rcin.org.pl/Content/13489/PDF/WA35_29830_5299_Principe.pdf},
}