@article{10_4064_ap_7_3_293_303,
     author = {Z. Opial},
     title = {Sur les solutions de classe $(L^2)$ de l'\'equation diff\'erentielle u'' + q(t)u = 0},
     journal = {Annales Polonici Mathematici},
     pages = {293--303},
     publisher = {mathdoc},
     volume = {7},
     number = {3},
     year = {1959},
     doi = {10.4064/ap-7-3-293-303},
     language = {fr},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/ap-7-3-293-303/}
}