@article{Sergeev2013a, author = "E. Sergeev and S. Grach and A. Shindin and E. Mishin and P. Bernhardt and S. Briczinski and B. Isham and M. Broughton and J. LaBelle and B. Watkins", title = "Artificial Ionospheric Layers during Pump Frequency Stepping Near the 4th Gyroharmonic at HAARP", year = 2013 , journal = "Phys. Rev. Lett.", volume = 110, number = 6, keywords = "amisr, muir", doi = "10.1103/PhysRevLett.110.065002" }