@misc{Yang_J._S._A_1991,
 author={Yang, J. S.},
 volume={43},
 number={6},
 copyright={Creative Commons Attribution BY 4.0 license},
 address={Warszawa},
 journal={Archives of Mechanics},
 howpublished={online},
 year={1991},
 publisher={Polish Scientific Publishers IFTR},
 language={eng},
 type={Text},
 title={A generalized variational principle for piezoelectromagnetism in an elastic medium},
 URL={http://rcin.org.pl/Content/70013/PDF/WA727_18042_43-6-1991_AMS_Yang-08.pdf},
 keywords={Mechanika stosowana - czasopisma [KABA]},
}