@article{MAN_1960__140_160782,
     author = {J.J. Sch\"affer},
     title = {Linear {Differential} {Equations} and {Functional} {Analysis.} {V.}},
     journal = {Mathematische Annalen},
     pages = {308--321},
     publisher = {mathdoc},
     volume = {140},
     year = {1960},
     zbl = {0099.07002},
     url = {http://geodesic.mathdoc.fr/item/MAN_1960__140_160782/}
}