@article{GDZPPN002416387, title = {Approximation with Restricted Spectra.}, journal = {Mathematische Zeitschrift}, volume = {142}, year = {1975}, pages = {289-297}, zbl = {0295.47028}, url = {http://dml.mathdoc.fr/item/GDZPPN002416387} }
Chui, C.K.; Smith, P.W.; Ward, J.D. Approximation with Restricted Spectra.. Mathematische Zeitschrift, Tome 142 (1975) pp. 289-297. http://gdmltest.u-ga.fr/item/GDZPPN002416387/