@article{ivanov1990waveguide,
  author = "S. Ivanov and E. Alexov and P. Malinov",
  title = "Waveguide partially filled with semiconductor plasma",
  year = 1990,
  journal = "Physica Scripta",
  publisher = "IOP Publishing",
  volume = 42,
  number = 4,
  pages = "452"
}