@misc{Langevin_Paul_(1872–1946)_Le_1950,
 author={Langevin, Paul (1872–1946)},
 copyright={Public Domain},
 address={Paris},
 howpublished={online},
 year={1950},
 publisher={CNRS},
 language={fre},
 type={Text},
 title={Le principe de relativité, Bibliothèque de Synthèese scientifique, E. Chiron, éditeur, Paris, 1922},
 URL={http://rcin.org.pl/Content/195769/PDF/WA35_226774_8818_Art23.pdf},
}