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;
Grabowski, R., Hanuise, C., Nielsen, E., Villain, J. P., & Wolf, H. (1985). Stimultaneous measurements of the ionospheric electric field by probes and radar methods. Journal of Atmospheric and Terrestrial Physics, 47, 41.