@misc{Ignaczak_J._Upper_1971,
 author={Ignaczak, J.},
 volume={23},
 number={6},
 copyright={Licencja Creative Commons Uznanie autorstwa 4.0},
 journal={Archives of Mechanics},
 address={Warszawa},
 howpublished={online},
 year={1971},
 publisher={Polish Scientific Publishers IFTR},
 language={eng, streszcz. eng, pol, ros},
 type={Tekst},
 title={Upper and lower bounds on the velocity of surface waves in a nonhomogenous isotropic elastic semi-space},
 keywords={Mechanika stosowana - czasopisma [KABA]},
}