@article{10_4064_ap_10_1_73_79,
     author = {Z. Opial},
     title = {Sur la limitation des d\'eriv\'ees des solutions born\'ees d'un syst\`eme d'\'equations diff\'erentielles du second ordre},
     journal = {Annales Polonici Mathematici},
     pages = {73--79},
     publisher = {mathdoc},
     volume = {10},
     number = {1},
     year = {1961},
     doi = {10.4064/ap-10-1-73-79},
     language = {fr},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/ap-10-1-73-79/}
}