Approximation properties of Bernstein singular integrals in variable   exponent Lebesgue spaces on the real axis
  In generalized Lebesgue spaces L^{p(.)} with variable exponent p(.) defined on the real axis, we obtain several inequalities of approximation by integral functions of finite degree. Approximation properties of Bernstein singular integrals in these spaces are obtained. Estimates of simultaneous approximation by integral functions of finite degree in L^{p(.)} are proved. 
Ramazan Akg\"un
math.CA