Schlegel, K. MPI for Aeronomy, Max Planck Institute for Solar System Research, Max Planck Society;
Link (Any fulltext)
Liu, H., Schlegel, K., & Ma, S.-Y. (2000). Combined ESR and EISCAT observations of the dayside polar cap and auroral oval during the May 15, 1997 storm. Annales Geophysicae, 18(9), 1067-1072.