Absolutely convergent double Fourier series, enlarged Lipschitz and Zygmund classes of functions of two variables

Móricz, F [Móricz, Ferenc (Fourier analízis), author] Bolyai Institute (Institute of Mathematics) (SZTE / TTIK); Sáfár, Z [Sáfár, Zoltán (analízis), author] Bolyai Institute (Institute of Mathematics) (SZTE / TTIK)