“…Later, in 1970, Lizorkin [57] further studied both the theory of multipliers of Fourier integrals and estimates of convolutions in the mixed-norm Lebesgue spaces. Moreover, very recently, there appears a renewed increasing interest in the theory of mixed-norm function spaces, including mixed-norm Lebesgue spaces, mixed-norm Hardy spaces, mixed-norm Besov spaces and mixed-norm Triebel-Lizorkin spaces; see, for example, [19,20,30,38,39,40,41]. For more developments of mixed-norm function spaces, we refer the reader to [16,18,27,29,42,43].…”