@article{ivanov1989symmetrical,
  author = "S. Ivanov and E. Alexov and P. Malinov",
  title = "Symmetrical electromagnetic waves in partially-filled plasma waveguide",
  year = 1989,
  journal = "Plasma physics and controlled fusion",
  publisher = "IOP Publishing",
  volume = 31,
  number = 6,
  pages = "941"
}