@article{10_4064_ap_7_1_51_61,
     author = {Z. Opial},
     title = {Sur les solutions presque-p\'eriodiques des \'equations diff\'erentielles du premier et du second ordre},
     journal = {Annales Polonici Mathematici},
     pages = {51--61},
     year = {1959},
     volume = {7},
     number = {1},
     doi = {10.4064/ap-7-1-51-61},
     language = {fr},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/ap-7-1-51-61/}
}