共 50 条
- [33] ON THE SPECTRUM OF 4TH-ORDER LINEAR INTEGRO-DIFFERENTIAL OPERATOR DOKLADY AKADEMII NAUK SSSR, 1988, 299 (03): : 525 - 529
- [37] LIMIT-POINT CRITERIA FOR POSITIVE DEFINITE FOURTH-ORDER DIFFERENTIAL OPERATORS QUARTERLY JOURNAL OF MATHEMATICS, 1973, 24 (95): : 367 - 376
- [38] 4TH-ORDER NONLINEAR OSCILLATIONS OF FUNCTIONAL-DIFFERENTIAL EQUATIONS JOURNAL OF THE LONDON MATHEMATICAL SOCIETY-SECOND SERIES, 1978, 18 (OCT): : 287 - 298