Röttger, J. MPI for Aeronomy, Max Planck Institute for Solar System Research, Max Planck Society;
Bremer, J., Singer, W., Keuer, D., Hoffmann, P., Röttger, J., Cho, J. Y. N., et al. (1995). Observations of polar mesosphere summer echoes at EISCAT during summer 1991. Radio Science, 30, 1219-1228.