共 11 条
- [2] Helffer B., 1979, Commun. Partial Differ. Equ., V4, P899
- [3] Miller K. G., 1980, COMMUN PART DIFF EQ, V5, P1153, DOI [10.1080/03605308008820166, DOI 10.1080/03605308008820166]
- [4] ROCKLAND C, 1978, T AM MATH SOC, V240, P1
- [5] HYPOELLIPTIC DIFFERENTIAL OPERATORS AND NILPOTENT GROUPS [J]. ACTA MATHEMATICA, 1976, 137 (3-4) : 247 - 320
- [6] [No title captured]
- [7] [No title captured]
- [8] [No title captured]
- [9] [No title captured]
- [10] [No title captured]