1-2 of 2 Books

On Necessary and Sufficient Conditions for L^p-estimates of Riesz Transforms Associated to Elliptic Operators on R^n and Related Estimates (Memoirs of the American Mathematical Society)
By Pascal Auscher

Calderón-Zygmund operators, pseudo-differential operators, and the Cauchy integral of Calderón
By Jean-Lin Journé