On planar harmonic Lipschitz and planar harmonic Hardy classes

In this paper, we investigate the properties of two classes of planar harmonic mappings. First, we discuss the equivalent norms on Lipschitz-type spaces of harmonic K-quasiregular mappings and then we study the relationship between the harmonic area functions and the harmonic Hardy classes. We also establish Landau's theorem for a class of harmonic Hardy mappings.