To the Sobolev embedding theorem for the limiting exponent

We establish embeddings of the Sobolev space $W_p^s$ and the space $B_{pq}^s$ (with the limiting exponent) in certain spaces of locally integrable functions of zero smoothness. This refines the embedding of the Sobolev space in the Lorentz and Lorentz–Zygmund spaces. Similar problems are considered for the case of irregular domains and for the potential space.