The Invariant Distance in the Theory of Pseudo-Conformal Transformations and the Lu Qikeng Conjecture
Maciej Skwarczyński · Proceedings of the American Mathematical Society · 1969
M. Skwarczynski, The Invariant Distance in the Theory of Pseudo-Conformal Transformations and the Lu Qikeng Conjecture, Proceedings of the American Mathematical Society, Vol. 22, No. 2 (Aug., 1969), pp. 305-310