共 50 条
- [1] ON THE PERTURBATION-THEORY FOR FREDHOLM OPERATORS [J]. OSAKA JOURNAL OF MATHEMATICS, 1984, 21 (03) : 603 - 612
- [9] PERTURBATION-THEORY OF DEFICIENCY INDEXES OF DIFFERENTIAL OPERATORS [J]. JOURNAL OF THE LONDON MATHEMATICAL SOCIETY-SECOND SERIES, 1976, 12 (48): : 405 - 412