Greenwald, R. A. MPI for Aeronomy, Max Planck Institute for Solar System Research, Max Planck Society;
Baumjohann, W., Untiedt, J., & Greenwald, R. A. (1980). Joint two-dimensional observations of ground magnetic and ionospheric electric fields associated with auroral zone currents. 1. Three-dimensional current flow associated with a substorm-intensified eastward electrojet. Journal Geophysical Research, 85, 1963.