Über primitive Ideale in der Einhüllenden einer halbeinfachen Lie-Algebra W. Borho; J.C. Jantzen — 1977 Inventiones mathematicae
Differential operators on homogeneous spaces. III. Characteristic varieties of Harish Chandra modules and of primitive ideals. W. Borho; J.-L. Brylinski — 1985 Inventiones mathematicae