@article{AM2_1975__12_136503,
     author = {M. Becker},
     title = {Linear approximation processes in locally convex spaces. {I.} {Semigroups} of operators and saturation. {(Short} {Communication).}},
     journal = {Aequationes mathematicae},
     pages = {120--120},
     publisher = {mathdoc},
     volume = {12},
     year = {1975},
     url = {http://geodesic.mathdoc.fr/item/AM2_1975__12_136503/}
}