Alexander I. Stepanets 
Methods of Approximation Theory [PDF ebook] 

i-iv – Contents – PREFACE – PART I – 1. REGULARITY OF LINEAR METHODS OF SUMMATION OF FOURIER SERIES – 2. SATURATION OF LINEAR METHODS – 3. CLASSES OF PERIODIC FUNCTIONS – 4. INTEGRAL REPRESENTATIONS OF DEVIATIONS OF POLYNOMIALS GENERATED BY LINEAR PROCESSES OF SUMMATION OF FOURIER SERIES – 5. APPROXIMATION BY FOURIER SUMS IN SPACES C AND L1 – BIBLIOGRAPHICAL NOTES (PART I) – REFERENCES (PART I) – PART II – 6. CONVERGENCE RATE OF FOURIER SERIES AND THE BEST APPROXIMATIONS IN THE SPACES Lp – 7. BEST APPROXIMATIONS IN THE SPACES C AND L – 8. INTERPOLATION – 9. APPROXIMATIONS IN THE SPACES OF LOCALLY SUMMABLE FUNCTIONS – 10. APPROXIMATION OF CAUCHY-TYPE INTEGRALS – 11. APPROXIMATIONS IN THE SPACES Sp – 12. APPROXIMATIONS BY ZYGMUND AND DE LA VALLÉE POUSSIN SUMS – BIBLIOGRAPHICAL NOTES (PART II) – REFERENCES (PART II) – Index