Nielsen, E. MPI for Aeronomy, Max Planck Institute for Solar System Research, Max Planck Society; Department Planets and Comets, Max Planck Institute for Solar System Research, Max Planck Society;
Wang, X.-D., Wang, J.-S., Nielsen, E., & Zou, H. (2009). ``Hook'' structure in MARSIS ionogram and its interpretation. Geophysical Research Letters, 36: L13103. doi:10.1029/2009GL038844.