@article{MAN_1963__150_161045,
     author = {J.J. Sch\"affer},
     title = {Linear {Differential} {Equations} and {Functional} {Analysis.} {IX.} {Almost} {Periodic} {Equations.}},
     journal = {Mathematische Annalen},
     pages = {111--118},
     publisher = {mathdoc},
     volume = {150},
     year = {1963},
     zbl = {0113.07001},
     url = {http://geodesic.mathdoc.fr/item/MAN_1963__150_161045/}
}