1. D. S. Anikonov, “On boundedness of a singular integral operator in the space Cα(Ḡ),” Mat. Sb., 104, No. 4, 516–534 (1977).
2. J. Bergh and J. LÖfstrÖm, Interpolation Spaces. An Introduction, Springer-Verlag, Berlin– Heidelberg–New York (1976).
3. L. Bers, F. John, and M. Schechter, Partial Differential Equations, Interscience Publishers, New York–London–Sydney (1964).
4. O. V. Besov, V. P. Ilin, and S. M. Nikolskii, Integral Representation of Functions and Embedding Theorems [in Russian], Nauka, Moscow (1975).
5. A. V. Bitsadze, “Spatial analog of the Cauchy-type integral and some its applications,” Dokl. AN SSSR, 93, No. 3, 389–392 (1953).