00529nam a2200157Ia 4500 240117b |||||||| |||| 00| 0 eng d 0677006853 515.72 R383.PT Rellich, Franz 1761 Perturbation theory of eigenvalue problems / New York: Gordon & Breach Science Publishers Ltd., 1969 x, 127p. Index Notes on Mathematics and its applications Berkowitz, J. 1762 author. ddc BK 0 0 0 515_720000000000000_R383_PT 0 15632 ISI ISI 1998-09-22 9 16 515.72 R383.PT DP13322 2026-10-19 2026-07-20 00:00:00 2026-07-20 BK 12900 12900