%0 Journal Article %A Ryszard Smarzewski %T On characterization of non-linear best Chebyshev approximations %J Colloquium Mathematicum %D 1980 %P 111-116 %V 43 %N 1 %I mathdoc %U http://geodesic.mathdoc.fr/articles/10.4064/cm-43-1-111-116/ %R 10.4064/cm-43-1-111-116 %G en %F 10_4064_cm_43_1_111_116