 Thus for embedded CR structures using the result of Kohn stated above, we conclude that the compact CR structure that is strongly pseudoconvex is embedded if and only if the Kohn Laplacian has positive eigenvalues that are bounded below by a positive constant.The Kohn Laplacian always has the eigenvalue zero corresponding to the CR functions.Estimates for formula_81 and formula_72 have been obtained in various function spaces in various settings.