@misc{Ciekot_Anita_Frequency,
 author={Ciekot, Anita and Kukla Stanisław},
 howpublished={online},
 publisher={Wydaw. Politechniki Częstochowskiej},
 language={eng},
 type={czasopismo},
 title={Frequency analysis of a double-walled nanotubes system},
 keywords={nanotubes system, free vibration, Green's functions},
}