1. [2] D. Birkes, Orbits of linear algebraic groups, Ann. of Math. (2) 93 (1971), 459–475.
2. [1] A. Beĭ linson, G. Lusztig, and R. MacPherson, A geometric setting for the quantum deformation of $\rm GL\sb n$, Duke Math. J. 61 (1990), no. 2, 655–677.
3. [3] W. Borho and R. MacPherson, Partial resolutions of nilpotent varieties, Analysis and topology on singular spaces, II, III (Luminy, 1981), Astérisque, vol. 101, Soc. Math. France, Paris, 1983, pp. 23–74.
4. [4] N. Chriss and V. Ginzburg, Representation theory and complex geometry, Birkhäuser Boston Inc., Boston, MA, 1997.
5. [5] W. Fulton, Intersection theory, Ergebnisse der Mathematik und ihrer Grenzgebiete (3) [Results in Mathematics and Related Areas (3)], vol. 2, Springer-Verlag, Berlin, 1984.