@article{CMJ_2003__53_3_a0,
     author = {Naulin, Ra\'ul},
     title = {On the instability of linear nonautonomous delay systems},
     journal = {Czechoslovak Mathematical Journal},
     pages = {497--514},
     publisher = {mathdoc},
     volume = {53},
     number = {3},
     year = {2003},
     mrnumber = {2000048},
     zbl = {1080.34543},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/CMJ_2003__53_3_a0/}
}