1. Krein S. G., Petunin Yu. I., Semenov E. M. Interpolyatsiya lineynykh operatorov. (Russian) [Interpolation of linear operators] “Nauka” , Moscow, 1978.
2. Bennett C., Sharpley R. Interpolation of operators. Pure Appl. Math. 129, Acad. Press, Boston, 1988.
3. Mazya V. G. Sobolev spaces. LSU, 1985.
4. Nikol’skii, S. M. Priblizhenie funktsii mnogikh peremennykh i teoremy vlozheniya. (Russian) [Approximation of functions of several variables and imbedding theorems] Second edition, revised and supplemented. “Nauka” , Moscow, 1969.
5. Stein, Elias M. Singular integrals and differentiability properties of functions. M:Mir, 1973.