@ARTICLE{
author={Covic Vukman M,Djuric Dragutin,Veskovic Miroslav M,Obradovic Aleksandar M},
year={2011},
title={Lyapunov-Kozlov method for singular cases},
journal={APPLIED MATHEMATICS AND MECHANICS-ENGLISH EDITION},
volume={32},
number={9},
pages={1207-1220},
document_type={Article},
} 

@ARTICLE{
author={Covic Vukman M,Veskovic Miroslav M,Djuric Dragutin,Obradovic Aleksandar M},
year={2010},
title={On the stability of equilibria of nonholonomic systems with nonlinear constraints},
journal={APPLIED MATHEMATICS AND MECHANICS-ENGLISH EDITION},
volume={31},
number={6},
pages={751-760},
document_type={Article},
} 

@ARTICLE{
author={Djuric Dragutin},
year={2007},
title={On stability of stationary motion of a nonconservative nonholonomic rheonomic system},
journal={EUROPEAN JOURNAL OF MECHANICS A-SOLIDS},
volume={26},
number={6},
pages={1029-1039},
document_type={Article},
}