共 50 条
- [1] POSITIVE DEFINITE FOURTH ORDER DIFFERENTIAL OPERATORS JOURNAL OF THE LONDON MATHEMATICAL SOCIETY-SECOND SERIES, 1973, 6 (MAY): : 412 - 416
- [2] 4TH-ORDER QUASI-REGULAR DIFFERENTIAL-OPERATORS DOKLADY AKADEMII NAUK SSSR, 1980, 251 (03): : 550 - 553
- [3] A 4TH-ORDER UNILATERAL DIFFERENTIAL PROBLEM IN 2 VARIABLES BOLLETTINO DELLA UNIONE MATEMATICA ITALIANA, 1983, 2B (02): : 653 - 664
- [9] BOUNDEDNESS OF A CERTAIN 4TH-ORDER DIFFERENTIAL EQUATION JOURNAL OF THE LONDON MATHEMATICAL SOCIETY-SECOND SERIES, 1975, 11 (OCT): : 313 - 324
- [10] LIMIT POINT CRITERIA POSITIVE DEFINITE FOURTH ORDER DIFFERENTIAL OPERATORS NOTICES OF THE AMERICAN MATHEMATICAL SOCIETY, 1972, 19 (07): : A796 - A796