@article{AM2_1968__1_182295,
     author = {E. Hille},
     title = {Some {Properties} of the {Jordan} {Operators.} {(Short} {Communication).}},
     journal = {Aequationes mathematicae},
     pages = {206--206},
     publisher = {mathdoc},
     volume = {1},
     year = {1968},
     url = {http://geodesic.mathdoc.fr/item/AM2_1968__1_182295/}
}