@misc{Langevin_Paul_(1872–1946)_Sur_1950,
 author={Langevin, Paul (1872–1946)},
 copyright={Public Domain},
 address={Paris},
 howpublished={online},
 year={1950},
 publisher={CNRS},
 language={fre},
 type={Text},
 title={Sur les biréfringences électrique et magnétique, Le Radium, 1910, 7, 249},
 URL={http://rcin.org.pl/Content/195743/PDF/WA35_226770_8818_Art19.pdf},
}