@ARTICLE{Duda_J._A_2013,
 author={Duda, J.},
 volume={61},
 number={No 4},
 journal={Bulletin of the Polish Academy of Sciences Technical Sciences},
 pages={911-918},
 howpublished={online},
 year={2013},
 title={A Lyapunov functional for a neutral system with a time-varying delay},
 URL={http://www.journals.pan.pl/Content/83831/PDF/19_paper.pdf},
 doi={10.2478/bpasts-2013-0098},
}