“…Under regularity assumptions analogous to (1.1) or (1.2), the theory has been developed through works of Coifman-Meyer [2], [3], [4], Christ-Journé [6], Kenig-Stein [15] and Grafakos-Torres [10], [11]. Some of the most recent work in the subject was motivated in part by the results of Lacey-Thiele [16], [17] on the bilinear Hilbert transform and a search for the optimal range of exponents where boundedness in Lebesgue spaces can be obtained. Unlike the case of the bilinear Hilbert transform, a more singular operator not covered by the Calderón-Zygmund theory, the boundeness of Calderón-Zygmund operators on the full range of exponents is known.…”