1. On a modification of the concept of the modulus of smoothness and its use in estimating Fourier coefficients (Russian);Zhuk;Dokl. Akad. Nauk SSSR,1965
2. On Fourier coefficients of functions of bounded variation (Russian);Potapov;Vestn. Moskov. Univ. Ser. I Mat. Meh.,1966
3. Fourierkoeffizienten und Funktionenklassen;Lorentz;Math. Z.,1948
4. Note on harmonic functions;Helson,1953
5. On a theorem of Szegö;Helson,1955