共 50 条
- [1] HYPOELLIPTICITY OF DIFFERENTIAL OPERATORS OF SECOND-ORDER WITH REAL COEFFICIENTS COMPTES RENDUS HEBDOMADAIRES DES SEANCES DE L ACADEMIE DES SCIENCES SERIE A, 1973, 277 (12): : 529 - 530
- [2] HYPOELLIPTICITY OF 2ND-ORDER DIFFERENTIAL OPERATORS WITH REAL COEFFICIENTS JOURNAL DE MATHEMATIQUES PURES ET APPLIQUEES, 1976, 55 (01): : 99 - 129
- [3] On the spectrum of second-order differential operators with complex coefficients PROCEEDINGS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES, 1999, 455 (1984): : 1235 - 1257
- [5] CHARACTERIZATION OF DIFFERENTIAL SECOND-ORDER OPERATORS ATTI DELLA ACCADEMIA NAZIONALE DEI LINCEI RENDICONTI-CLASSE DI SCIENZE FISICHE-MATEMATICHE & NATURALI, 1973, 54 (03): : 365 - 372
- [8] Second-order differential operators with interior singularity Advances in Difference Equations, 2015
- [10] Second-order differential operators with interior singularity ADVANCES IN DIFFERENCE EQUATIONS, 2015,