In the 1970's,Folland and Stein studied a family of subelliptic scalar operators Lλ which arise naturally in the (-e)b-complex.They introduced weighted Sobolev spaces as the natural spaces for this complex,and then obtained sharp estimates for (-e)b in these spaces using integral kernels and approximate-inverses.In the 1990's,Rumin introduced a differential complex for compact contact manifolds,showed that the Folland-Stein operators are central to the analysis for the corresponding Laplace operator,and derived the necessary estimates for the Laplacian from the Folland Stein analysis.In this paper,we give a self-contained derivation of sharp estimates in the anisotropic Folland-Stein spaces for the operators studied by Rumin using integration by parts and a modified approach to bootstrapping.