@article{MZ_1977__156_172565,
     author = {Itshak Borosh and C.K. Chui and P.W. Smith},
     title = {Best {Uniform} {Approximation} from a {Collection} of {Subspaces.}},
     journal = {Mathematische Zeitschrift},
     pages = {13--18},
     year = {1977},
     volume = {156},
     zbl = {0366.41012},
     url = {http://geodesic.mathdoc.fr/item/MZ_1977__156_172565/}
}