@article{RCM_1991__25_1-4_181849,
     author = {Ra\'ul Naulin},
     title = {A conterexample in the theory of linear singularly perturbed systems},
     journal = {Revista colombiana de matematicas},
     pages = {95--102},
     publisher = {mathdoc},
     volume = {25},
     number = {1-4},
     year = {1991},
     zbl = {0767.34042},
     url = {http://geodesic.mathdoc.fr/item/RCM_1991__25_1-4_181849/}
}