Voir la notice de l'article provenant de la source Novi sad journal of mathematics website
@article{NSJOM_1993_23_2a_9, author = {Kulenovi\'c Mustafa R. S. and Budin\v{c}evi\'c Mirko}, title = {Perturbatons of a linear differential equation}, journal = {Novi Sad Journal of Mathematics}, pages = {113-120}, publisher = {mathdoc}, volume = {23}, number = {2}, year = {1993}, url = {http://geodesic.mathdoc.fr/item/NSJOM_1993_23_2a_9/} }
Kulenović Mustafa R. S.; Budinčević Mirko. Perturbatons of a linear differential equation. Novi Sad Journal of Mathematics, Tome 23 (1993) no. 2. http://geodesic.mathdoc.fr/item/NSJOM_1993_23_2a_9/