@article{10_4064_ap_5_2_153_164,
     author = {Z. Opial},
     title = {Sur un probl\`eme de stabilit\'e},
     journal = {Annales Polonici Mathematici},
     pages = {153--164},
     publisher = {mathdoc},
     volume = {5},
     number = {2},
     year = {1958},
     doi = {10.4064/ap-5-2-153-164},
     language = {fr},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/ap-5-2-153-164/}
}