A theory of absolutely continuous transformations in the plane
Tibor Radó, Paul V. Reichelderfer · Transactions of the American Mathematical Society · 1941
Some properties of continuous transformations in the plane; received by the editors June 6, 1940.(') The class of transformations which are absolutely continuous, in our sense, in a domain D will be denoted by isTi(D), and will be described in 1.32.