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