1. Sur la meilleure approximation de |x| par des polynômes des degrés donnés;Bernstein;Acta Math.,1913
2. Sur la meilleure approximation de |x|p par des polynômes de degrés trés élevés;Bernstein;Izv. Akad. Nauk SSSR Ser. Mat.,1938
3. S.N. Bernstein, Extremal Properties of Polynomials and the Best Approximation of Continuous Functions of a Single Real Variable, State United Scientific and Technical Publishing House, Moscow, 1937 (in Russian).
4. Timan's type result on approximation by algebraic polynomials;Brudnyi;Oper. Theory, Adv. Appl.,1997
5. Polynomial approximation of piecewise analytic functions;Gaier;J. Anal.,1996