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;
Chen, P.-R., Yi, L., & Nielsen, E. (1995). Variations of the mean phase velocity of 1-m ionospheric plasma waves with the plasma electron temperature. Journal Geophysical Research, 100, 1647-1652.