%0 Journal Article
%A Butzer, P. L.
%A Dyckhoff, H.
%A Görlich, E.
%A Stens, R. L.
%T Best Trigonometric Approximation, Fractional Order Derivatives and Lipschitz Classes
%J Canadian journal of mathematics
%D 1977
%P 781-793
%V 29
%N 4
%U http://geodesic.mathdoc.fr/articles/10.4153/CJM-1977-081-6/
%R 10.4153/CJM-1977-081-6
%F 10_4153_CJM_1977_081_6