TY  - RPRT
TI  - Lower bounds for eigenvalues of self-adjoint problems.
AU  - G G Gundersen
PY  - 1979
DO  - 10.1073/pnas.76.11.5424
UR  - https://pubmed.ncbi.nlm.nih.gov/16592718/
ID  - 16592718
ER  -