@article{EJDE_2004__2004__a128,
     author = {Carja,  Ovidiu and Necula,  Mihai and Vrabie,  Ioan I.},
     title = {Local invariance via comparison functions},
     journal = {Electronic journal of differential equations},
     year = {2004},
     volume = {2004},
     zbl = {1058.34063},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/EJDE_2004__2004__a128/}
}