@article{10_4064_ap_7_2_223_231,
     author = {Z. Opial},
     title = {Sur un probl\`eme aux limites pour l'\'equation diff\'erentielle du second ordre},
     journal = {Annales Polonici Mathematici},
     pages = {223--231},
     publisher = {mathdoc},
     volume = {7},
     number = {2},
     year = {1959},
     doi = {10.4064/ap-7-2-223-231},
     language = {fr},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/ap-7-2-223-231/}
}