On the Laguerre calculus of left-invariant convolution (pseudo-differential) operators on the Heisenberg group Peter C. Greiner Séminaire Équations aux dérivées partielles (Polytechnique)
LP and Lipschitz Estimates for the ... Equation and the ...-Neumann Problem. Nancy K. Stanton; Richard Beals; Peter C. Greiner — 1987 Mathematische Annalen