1. Über Bahnen and deren Deformationen bei linearen Aktionen reduktiver Gruppen;Borho;Comment. Math. Helv.,1979
2. Groupes et Algèbres de Lie, chap. 7 et 8, CCLS Diffusion;Bourbaki,1975
3. The variety of all invariant symplectic structures on a homogeneous space and normalizers of isotropy groups;Brylinski,1991
4. Algèbres Enveloppantes;Dixmier,1974
5. Construction of primitive ideals in an enveloping algebra;Duflo,1975