1. S. V. Bockariev, The logaritmic growth of the aritmetic means of the Lebesgue functions with respect to bounded orthonormal systems,DAN SSSR,223 (1975), 16–19 (in Russian).
2. J. A. Chao, Hardy spaces on regular martingales, Martingale Theory in Harmonic Analysis and Banach Spaces, Cleveland, Ohio, 1981, 18–28.,Lecture Notes in Mathematics,939, Springer (Berlin).
3. J. D. Chen, A theorem of Kaczmarz on multiple generalized Walsh-Fourier series,Bull. Inst. Math. Acad. Sinica,10 (1982), 205–212.
4. R.R. Coifman, G. L. Weiss, Extensions of Hardy spaces and their use in analysis,Bull. Amer. Math. Soc.,83 (1977), 569–645.
5. B. I. Golubov, On a class of complete orthogonal systems,Sib. Mat. Z.,9 (1968), 297–314 (in Russian).