TY  - JOUR
AU  - Georg Still
TI  - Computable Bounds for Eigenvalues and Eigenfunctions of Elliptic Differential Operators.
JO  - Numerische Mathematik
PY  - 1989
SP  - 201
EP  - 224
VL  - 54
IS  - 3
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/NUMA_1989__54_3_133314/
ID  - NUMA_1989__54_3_133314
ER  -