@misc{indiciaed9abe62a88d3,
  title = {Spectral gaps for electromagnetic and scalar waves: Possible explanation for certain differences.},
  author = {MM Sigalas and EN Economou and M Kafesaki},
  year = {1994},
  doi = {10.1103/physrevb.50.3393},
  url = {https://pubmed.ncbi.nlm.nih.gov/9976594/},
  note = {Source identifier: 9976594}
}