The book before the reader is devoted to an exposition of results of investigations carried out mainly over the last 10-15 years concerning certain questions in the theory of quasiconformal mappings. The principal objects of investigation-mappings with bounded distortion- are a kind of n-space analogue of holomorphic functions. As is known, every holomorphic function is characterized geometrically by the fact that the niapping of a planar domain it implements is conformal. In the n-space case the condition of conformality singles out a very narrow class of mappings. As Liouville showed back in 1850, already in threedimensional Euclidean space there are no conformal mappings besides those which are compositions of finitely.
