PEI, Lijun; CHEN, Fuyong. Sucient, necessary and i conditions of the stability of the coecients-time-varying linear system with time delays. International Journal of Novel Ideas: Mathematics, [S.l.], v. 2, p. 1-13, mar. 2018. ISSN 2331-5210. Available at: <http://www.sci-en-tech.com/IJNI/index.php/Math/article/view/116>. Date accessed: 20 oct. 2019.