Krotov V. G.: Note on the convergence of Fourier series in the spaces ΛPω. In: Acta scientiarum mathematicarum, (41) 3-4. pp. 335-338. (1979)
Krotov V. G. and Leindler László: On the strong summability of Fourier series and the classes Hω. In: Acta scientiarum mathematicarum, (40) 1-2. pp. 93-98. (1978)