@article{199,
  author = {B. Granger and Chris Greene},
  title = {Extending closed-orbit theory using quantum-defect ideas: Basic concepts and derivations},
  year = {2000},
  journal = {Physical Review A},
  volume = {62},
  month = {Jan-07-2000},
  issn = {1050-2947},
  doi = {10.1103/PhysRevA.62.012511},
}