@misc{indiciae735fb6bc04ce,
  title = {Eigenvalue equation for a general periodic potential and its multipole expansion solution.},
  author = {E Badralexe and AJ Freeman},
  year = {1988},
  doi = {10.1103/physrevb.37.1067},
  url = {https://pubmed.ncbi.nlm.nih.gov/9944613/},
  note = {Source identifier: 9944613}
}