1. V. S. Belonosov, “Classical solutions of quasi-elliptic equations,” Mat. Sb., 190, No. 9, 21–40 (1999).
2. O. V. Besov, V. P. Il’in, and S. M. Nikol’skii, Integral Representation of Functions and Embedding Theorems [in Russian], Nauka, Fizmatlit, Moscow (1996).
3. B. Bojarski, “Sharp maximal operator of fractional order and Sobolev imbedding inequalities,” Bull. Polish Acad. Sci. Math., 33, No. 1–2, 7–16 (1985).
4. L. Carleson, Selected Problems of Exceptional Set Theory [Russian translation], Mir, Noscow (1971).
5. L. Carleson, “Removable singularities for continuous harmonic functions in ℝ n ,” Math. Scand., 12, 15–18 (1963).