TY  - JOUR
AU  - N. Aronszajn
AU  - R. Brown
TI  - Finite-dimensional perturbations of spectral problems and variational approximation methods for eigenvalue problems. Part I. Finite-dimensional perturbations
JO  - Studia Mathematica
PY  - 1970
SP  - 1
EP  - 76
VL  - 36
IS  - 1
UR  - http://geodesic.mathdoc.fr/articles/10.4064/sm-36-1-1-76/
DO  - 10.4064/sm-36-1-1-76
LA  - en
ID  - 10_4064_sm_36_1_1_76
ER  -