TY  - RPRT
TI  - General approach to the envelope-function approximation based on a quadrature method.
AU  - R Winkler
AU  - U Rössler
PY  - 1993
DO  - 10.1103/physrevb.48.8918
UR  - https://pubmed.ncbi.nlm.nih.gov/10007111/
ID  - 10007111
ER  -