1. O. V. Besov, “Embedding of Sobolev space in the case of the limit exponent,” Mat. Zametki 98 (4), 498–510 (2015) [Math. Notes 98 (3–4), 550–560 (2015)].
2. O. V. Besov, V. P. Il’in, and S. M. Nikol’skii, Integral Representations of Functions and Embedding Theorems (Nauka, Moscow, 1996) [in Russian].
3. O. V. Besov, “Embedding of Sobolev spaces and properties of the domain,” Mat. Zametki 96 (3), 343–349 (2014) [Math. Notes 96 (3–4), 326–331 (2014)].
4. O. V. Besov, “Embedding of a weighted Sobolev space and properties of the domain,” in Trudy Mat. Inst. Steklov, Vol. 289: Selected Questions of Mathematics and Mechanics (MAIK, Moscow, 2015), pp. 107–114 [Proc. Steklov Inst. Math. 289, 96–103 (2015)].
5. T. Kilpelôinen and J. Malý, “Sobolev inequalities on sets with irregular boundaries,” Z. Anal. Anwendungen 19 (2), 369–380 (2000).