@article{IM_1976__34_142397,
     author = {Christer Borell},
     title = {Approximation on {Locally} {Convex} {Spaces.}},
     journal = {Inventiones mathematicae},
     pages = {215--230},
     year = {1976},
     volume = {34},
     zbl = {0315.46032},
     url = {http://geodesic.mathdoc.fr/item/IM_1976__34_142397/}
}