The asymptotic expansion of a CR invariant and Grauert tubes. Su-Jen Kann (1996) Mathematische Annalen
The topology of Stein CR manifolds and the Lefschetz theorem C. Denson Hill, Mauro Nacinovich (1993) Annales de l'institut Fourier Necessary topological conditions are given for the closed CR embedding of a CR manifold into a Stein manifold or into a complex projective space.