1. Golubov, B.I., “Best approximations of functions in L
p
metric by the Haar and Walsh polynomials”, Mat. Sbornik, Vol. 87, No. 2, 1972, 254-274.
2. Golubov, B.I., Efimov, A.V., Skvortsov, V.A., Walsh Series and Transforms - Theory and Applications, Moscow, Nauka, 1987, 344p, (in Russian).
3. Golubov, B.I., “On the modified strong dyadic integral and derivative”, Mat. Sbornik., Vol. 193, No 4, 2002, 37-60.
4. Butzer, P. L., Wagner, H. J., “Walsh series and the concept of a derivative”, Applicable Anal., Vol. 3, 1973, 29-46.
5. ∗Butzer, P. L., Wagner, H. J., “A calculus for Walsh functions defined on R
+”, Proc. Symp. Applications of Walsh functions, Washington, D. C., April 18 - 20, 1973, 75-81.