Wilhelm, K. MPI for Aeronomy, Max Planck Institute for Solar System Research, Max Planck Society; Department Sun and Heliosphere, Max Planck Institute for Solar System Research, Max Planck Society;
Wilhelm, K., & Kalkofen, W. (2003). Observations of the upper solar chromosphere with SUMER. Astronomy and Astrophysics, 408, 1137-1154.