TY  - RPRT
TI  - Variational method for approximating energy levels.
AU  - Y Zhou
AU  - JD Mancini
AU  - PF Meier
AU  - SP Bowen
PY  - 1995
DO  - 10.1103/physreva.51.3337
UR  - https://pubmed.ncbi.nlm.nih.gov/9911973/
ID  - 9911973
ER  -