This book is an introduction to the theory of quasiregular mappings in
real n-dimensional space, a new field of mathematical study that has
emerged during the past 20 years. The exposition is self-contained and
thus accessible to a wide readership. A broad spectrum of results of
both analytic and geometric character are presented, and the methods
vary accordingly. The main tools are the variational integral method and
the extremal length method, both of which are thoroughly developed here.
The author is noted as one of the developers of the theory of
quasiregular mappings, particularly for his work in value distribution
theory. Many of the topics treated here are published for the first time
in book form.