1. Representation of elliptic operators in an enveloping algebra;Nelson;Amer. J. Math.,1959
2. Differential Geometry and Symmetric Spaces;Helgason,1962
3. On C∞-vectors and intertwining bilinear forms for representations of Lie groups;Poulsen;J. Funct. Anal.,1972
4. Les C∗-algèbres et Leurs Représentations;Dixmier,1964
5. Analytic and entire vectors for representations of Lie groups;Goodman;Trans. Amer. Math. Soc.,1969